We may, from time to time, offer and sell debt securities, common stock, preferred stock, depositary shares, warrants and units. We may offer and sell these securities from time to time in amounts, at prices and on terms that will be determined at the time of the applicable offering.

This prospectus describes some of the general terms that may apply to these securities. We will provide the specific terms of any securities to be offered in a supplement to this prospectus. Any prospectus supplement may also add, update or change information contained in this prospectus. You should read this prospectus and any supplement carefully before you invest.

Our common stock is listed on The Nasdaq Capital Market (“Nasdaq”) under the symbol “THRY”. On July 29, 2022, the last reported sale price for our common stock was $24.34 per share.

We may offer and sell these securities to or through one or more underwriters, dealers or agents, or directly to purchasers, on a continuous or delayed basis. The prospectus supplement for each offering of securities will describe in detail the plan of distribution.

This prospectus may not be used to sell securities unless accompanied by a prospectus supplement.

Investing in our securities involves risk. You should carefully read the information under the heading “Risk Factors” on page 4 of this prospectus and the risk factors contained in any applicable prospectus supplement before making a decision to purchase our securities.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This prospectus is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission (the “SEC”), using a “shelf” registration process as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended (the “Securities Act”). Under this shelf process, we may, from time to time, sell the securities or combinations of the securities described in this prospectus in one or more offerings. This prospectus provides you with a general description of the securities that we may offer. Each time we offer securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement also may add, update or change information contained in this prospectus. Any statement that we make in this prospectus will be modified or superseded by any inconsistent statement made by us in a prospectus supplement.

You should rely only on the information contained or incorporated by reference in this prospectus and any prospectus supplement. We have not authorized anyone to provide you with additional or different information. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus and any prospectus supplement are not an offer to sell or the solicitation of an offer to buy any securities other than the securities to which they relate and are not an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make an offer or solicitation in such jurisdiction. You should not assume that the information contained in this prospectus or any prospectus supplement, as well as the information we previously filed with the SEC that we incorporate by reference in this prospectus or any prospectus supplement, is accurate as of any date other than the date on the front cover of the prospectus, or that the information incorporated by reference is accurate as of any date other than the date of the document incorporated by reference, regardless of the time of delivery of this prospectus or any sale of any security. Our business, financial condition, results of operations and prospects may have changed since those dates.

Additional information, including our financial statements and the notes thereto, is incorporated in this prospectus by reference to our reports filed with the SEC. Please read “Where You Can Find More Information” below. You are urged to read this prospectus carefully, including “Risk Factors,” any prospectus supplement and the documents incorporated by reference in their entirety before investing in our common stock.

In this prospectus, the “Company,” “Thryv,” “we,” “us,” “our” and similar terms refer to Thryv Holdings, Inc. and its subsidiaries, unless we state otherwise or the context indicates otherwise.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. We also filed a registration statement on Form S-3, including exhibits, under the Securities Act with respect to the securities offered by this prospectus. This prospectus is a part of the registration statement, but does not contain all of the information included in the registration statement or the exhibits. You can find our public filings with the SEC on the internet at a web site maintained by the SEC located at http://www.sec.gov. We also make available on our internet website our annual, quarterly and current reports and amendments as soon as reasonably practicable after such documents are electronically filed with, or furnished to, the SEC. Our Internet address is www.thryv.com. The information on our website is not incorporated by reference into this prospectus and does not constitute a part of this prospectus.

We are “incorporating by reference” specified documents that we file with the SEC, which means:

We incorporate by reference the documents listed below (excluding any information furnished and not filed with the SEC), which we filed with the SEC under the Securities Exchange Act of 1934, as amended (the “Exchange Act”):

In addition, we incorporate by reference in this prospectus any future filings made by the Company with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Exchange Act (excluding any information furnished and not filed with the SEC) after the date on which the registration statement that includes this prospectus was initially filed with the SEC and until all offerings under this shelf registration statement are terminated.

Any statement contained in a document incorporated by reference herein shall be deemed to be modified or superseded for all purposes to the extent that a statement contained in this prospectus or in any other subsequently filed document which is also incorporated or deemed to be incorporated by reference, modifies or supersedes such statement. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus. You may request a copy of these filings (other than an exhibit to a filing unless that exhibit is specifically incorporated by reference into that filing) at no cost by writing or telephoning us at the following address and telephone number, or emailing us at InvestorRelations@thryv.com:

This prospectus contains forward-looking statements that reflect our current views with respect to future events and financial performance. Such statements are provided under the “safe harbor” protection of the Private Securities Litigation Reform Act of 1995 and include, without limitation, statements concerning the conditions of our industry and our operations, performance, and financial condition, including, in particular, statements relating to our business, growth strategies, product development efforts, and future expenses. Forward-looking statements include all statements that do not relate solely to historical or current facts and generally can be identified by words such as “anticipates,” “intends,” “plans,” “seeks,” “believes,” “could,” “estimates,” “expects,” “likely,” “may,” and similar references to future periods, or by the inclusion of forecasts or projections. Examples of forward-looking statements include, but are not limited to, statements we make regarding the outlook for our future business and financial performance.

Forward-looking statements are based on our current expectations and assumptions regarding our business, the economy, and other future conditions. Because forward-looking statements relate to the future, by their nature, they are subject to inherent uncertainties, risks, and changes in circumstances that are difficult to predict. As a result, our actual results may differ materially from those contemplated by the forward-looking statements. Accordingly, we caution you against relying on forward-looking statements. Important factors that could cause actual results to differ materially from those in the forward-looking statements include regional, national, or global political, economic, business, competitive, market, and regulatory conditions and the following:

For additional information regarding known material factors that could cause the Company’s actual results to differ from its projected results, see those set forth in “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2021, in any accompanying prospectus supplement and in other filings made by us from time to time with the SEC or in materials incorporated herein or therein. Readers are cautioned not to place undue reliance on forward-looking statements contained in this prospectus, which speak only as of the date of this prospectus, and all forward-looking statements incorporated by reference into this prospectus speak only as of the dates such statements were made. Except as required by applicable law, the Company undertakes no obligation to update or revise any forward-looking statements publicly after the date they are made, whether as a result of new information, future events, or otherwise.

We are a global software and marketing services company that empowers small- to medium-sized businesses (“SMBs”), franchises, and agencies to grow and modernize their operations so they can compete and win in today’s economy. Over 46,000 businesses use our award-winning SaaS platform, Thryv®, to manage their end-to-end customer experience, which has helped businesses across the U.S. and overseas grow their bottom line. We also manage digital and print presence for over 400,000 businesses, connecting these SMBs to local consumers via proprietary local search portals and print directories.

Our executive offices are located at 2200 West Airfield Drive, P.O. Box 619810 DFW Airport, Texas, 75261, and our telephone number is (972) 453-7000. Our website is www.thryv.com. We make our periodic reports and other information filed with or furnished to the SEC available free of charge through our website as soon as reasonably practicable after those reports and other information are electronically filed with or furnished to the SEC. Information on our website or any other website is not incorporated by reference into, and does not constitute a part of, this prospectus.

An investment in our securities involves a high degree of risk. You should carefully consider the risk factors and all of the other information included in, or incorporated by reference into, this prospectus, including those included in our most recent Annual Report on Form 10-K, any subsequently filed Quarterly Reports on Form 10-Q and any subsequently filed Current Reports on Form 8-K, which are incorporated herein by reference, and those risk factors that may be included in any applicable prospectus supplement, together with all the other information included in this prospectus, any prospectus supplement and the documents we incorporate by reference, in evaluating an investment in our securities. If any of these risks were to occur, our business, financial condition or results of operations could be adversely affected.

Unless we otherwise specify in the applicable prospectus supplement, we expect to use the net proceeds from the sale of the securities covered by this prospectus for general corporate purposes, which may include repayment or refinancing of borrowings, working capital, capital expenditures, investments and acquisitions. Any specific allocation of the net proceeds of an offering of securities to a specific purpose will be determined at the time of the offering and will be described in an accompanying prospectus supplement. Until we use the net proceeds from the sale of the securities for these purposes, we may place the net proceeds in temporary investments.

The debt securities that we may offer by this prospectus consist of notes or other evidences of indebtedness of Thryv. We may issue debt securities in one or more series under an indenture (the “Base Indenture”), between us and Computershare Trust Company, N.A., as trustee (the “Trustee”), which Base Indenture may from time to time be supplemented or amended by one or more indentures supplemental thereto entered into pursuant to the applicable provisions of the Base Indenture, including, for all purposes of the Base Indenture and any such supplemental indenture, the provisions of the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”) that are deemed to be a part of and govern the Base Indenture and any such supplemental indenture (the Base Indenture, any such supplemental indenture, and any such applicable provisions, collectively, an “Indenture”). The term “Indenture” shall also include the terms of any particular series or specific debt securities within a series established as contemplated by an Indenture. A form of the Base Indenture, which has been filed as an exhibit to the registration statement of which this prospectus is a part, is incorporated herein by reference. Except as otherwise defined in this prospectus, capitalized terms used in this prospectus have the meanings given to them in the Base Indenture. For purposes of this Description of Debt Securities, references to “Thryv,” the “Company,” “we,” “our” and “us” refer only to Thryv Holdings, Inc. and not to its subsidiaries.

The provisions of the Base Indenture will generally be applicable to all of the debt securities. Selected provisions of the Base Indenture are described in this prospectus. Additional or different provisions that are applicable to a particular series of debt securities will, if material, be described in a prospectus supplement relating to the offering of debt securities of that series. These provisions may include, among other things and to the extent applicable, the following:

Unless otherwise expressly stated or the context otherwise requires, as used in this section, the term “guaranteed debt securities” means debt securities that, as described in the prospectus supplement relating thereto, are guaranteed by one or more guarantors pursuant to the applicable supplemental indenture.

We may issue debt securities at a discount from their stated principal amount. Federal income tax considerations and other special considerations applicable to any debt security issued with original issue discount (an “original issue discount security”) may be described in an applicable prospectus supplement.

If the purchase price of any series of the debt securities is payable in a foreign currency or currency unit or if the principal of or any premium or interest on any series of the debt securities is payable in a foreign currency or currency unit, the restrictions, elections, general tax considerations, specific terms, and other information with respect to the debt securities and the applicable foreign currency or currency unit will be set forth in an applicable prospectus supplement.

Unless otherwise indicated in an applicable prospectus supplement:

We will issue each debt security only in registered form, without coupons, unless we specify otherwise in the applicable prospectus supplement. In addition, we will issue each debt security in global (i.e., book-entry)

form only, unless we specify otherwise in the applicable prospectus supplement. Debt securities in book-entry form will be represented by a global security registered in the name of a depositary, which will be the holder of all the debt securities represented by the global security. Those who own beneficial interests in a global debt security will do so through participants in the depositary’s securities clearance system, and the rights of these indirect owners will be governed solely by the applicable procedures of the depositary and its participants. References to “holders” in this description mean those who own debt securities registered in their own names, on the books that we or the Trustee maintain for this purpose, and not those who own beneficial interests in debt securities registered in street name or in debt securities issued in book-entry form through one or more depositaries.

Unless otherwise indicated in the applicable prospectus supplement, the following is a summary of the depositary arrangements applicable to debt securities issued in global form and for which The Depository Trust Company (“DTC”) acts as depositary.

Each global debt security will be deposited with, or on behalf of, DTC, as depositary, or its nominee, and registered in the name of a nominee of DTC. Except under the limited circumstances described below, global debt securities are not exchangeable for definitive certificated debt securities.

Ownership of beneficial interests in a global debt security is limited to institutions that have accounts with DTC or its nominee, or persons that may hold interests through those participants. In addition, ownership of beneficial interests by participants in a global debt security will be evidenced only by, and the transfer of that ownership interest will be effected only through, records maintained by DTC or its nominee for a global debt security.

Ownership of beneficial interests in a global debt security by persons that hold those interests through participants will be evidenced only by, and the transfer of that ownership interest within that participant will be effected only through, records maintained by that participant. DTC has no knowledge of the actual beneficial owners of the debt securities. Beneficial owners will not receive written confirmation from DTC of their purchase, but beneficial owners are expected to receive written confirmations providing details of the transaction, as well as periodic statements of their holdings, from the participants through which the beneficial owners entered the transaction. The laws of some jurisdictions require that certain purchasers of securities take physical delivery of securities they purchase in definitive form. These laws may impair your ability to transfer beneficial interests in a global debt security.

We will make payment of principal of, and interest and premium, if any, on, debt securities represented by a global debt security registered in the name of or held by DTC or its nominee to DTC or its nominee, as the case may be, as the registered owner and holder of the global debt security representing those debt securities. DTC has advised us that upon receipt of any payment of principal of, or interest and premium, if any, on, a global debt security, DTC will immediately credit accounts of participants on its book-entry registration and transfer system with payments in amounts proportionate to their respective interests in the principal amount of that global debt security, as shown in the records of DTC. Payments by participants to owners of beneficial interests in a global debt security held through those participants will be governed by standing instructions and customary practices, and will be the sole responsibility of those participants, subject to any statutory or regulatory requirements that may be in effect from time to time.

Neither we, any guarantor, any trustee nor any of our respective agents will be responsible for any aspect of the records of DTC, any nominee or any participant relating to, or payments made on account of, beneficial interests in a global debt security or for maintaining, supervising or reviewing any of the records of DTC, any nominee or any participant relating to such beneficial interests.

A global debt security is exchangeable for definitive debt securities registered in the name of, and a transfer of a global debt security may be registered to, any person other than DTC or its nominee, only if:

Any global debt security that is exchangeable pursuant to the preceding sentence will be exchangeable in whole for definitive debt securities in registered form, of like tenor and of an equal aggregate principal amount

as the global debt security, in denominations specified in the applicable prospectus supplement, if other than $2,000 and multiples of $1,000. The definitive debt securities will be registered by the registrar in the name or names instructed by DTC. We expect that these instructions may be based upon directions received by DTC from its participants with respect to ownership of beneficial interests in the global debt security.

Except as provided above, owners of the beneficial interests in a global debt security will not be entitled to receive physical delivery of debt securities in definitive form and will not be considered the holders of debt securities for any purpose under an Indenture. Except as provided above, no global debt security shall be exchangeable except for another global debt security of like denomination and tenor to be registered in the name of DTC or its nominee. Accordingly, each person owning a beneficial interest in a global debt security must rely on the procedures of DTC and, if that person is not a participant, on the procedures of the participant through which that person owns its interest, to exercise any rights of a holder under the global debt security or an Indenture.

We understand that, under existing industry practices, in the event that we request any action of holders, or an owner of a beneficial interest in a global debt security desires to take any action that a holder is entitled to take under the debt securities or an Indenture, DTC would authorize the participants holding the relevant beneficial interests to take that action. Additionally, those participants would authorize beneficial owners owning through those participants to take that action or would otherwise act upon the instructions of beneficial owners owning through them.

DTC has advised us that it is a limited-purpose trust company organized under the laws of the State of New York, a “banking organization” within the meaning of the New York Banking Law, a member of the Federal Reserve System, a “clearing corporation” within the meaning of the New York Uniform Commercial Code, and a “clearing agency” registered under the Exchange Act. DTC was created to hold securities of its participants and to facilitate the clearance and settlement of transactions among its participants in securities through electronic book-entry changes in accounts of the participants. By doing so, DTC eliminates the need for physical movement of securities certificates. DTC’s participants include securities brokers and dealers, banks, trust companies, clearing corporations, and certain other organizations. Access to DTC’s book-entry system is also available to others, such as banks, brokers, dealers, and trust companies that clear through or maintain a custodial relationship with a participant, either directly or indirectly. The rules applicable to DTC and its participants are on file with the SEC.

Investors may hold interests in the debt securities outside the U.S. through the Euroclear System (“Euroclear”) or Clearstream Banking (“Clearstream”) if they are participants in those systems, or indirectly through organizations which are participants in those systems. Euroclear and Clearstream will hold interests on behalf of their participants through customers’ securities accounts in Euroclear’s and Clearstream’s names on the books of their respective depositaries, which in turn will hold such interests in customers’ securities accounts in the depositaries’ names on the books of DTC.

Euroclear advises that it was created in 1968 to hold securities for participants of Euroclear (“Euroclear Participants”) and to clear and settle transactions between Euroclear Participants through simultaneous electronic book-entry delivery against payment, thereby eliminating the need for physical movement of certificates and any risk from lack of simultaneous transfers of securities and cash. Euroclear includes various other services, including securities lending and borrowing and interfaces with domestic markets in several countries. Euroclear is operated by the Euroclear S.A./N.V. (the “Euroclear Operator”), under contract with Euroclear Clearance Systems S.C., a Belgian cooperative corporation (the “Cooperative”). All operations are conducted by the Euroclear Operator, and all Euroclear securities clearance accounts and Euroclear cash accounts are accounts with the Euroclear Operator, not the Cooperative. The Cooperative establishes policy for Euroclear on behalf of Euroclear Participants. Euroclear Participants include banks (including central banks), securities brokers and dealers, and other professional financial intermediaries and may include any agents. Indirect access to Euroclear is also available to other firms that clear through or maintain a custodial relationship with a Euroclear Participant, either directly or indirectly.

Securities clearance accounts and cash accounts with the Euroclear Operator are governed by the Terms and Conditions Governing Use of Euroclear, the related Operating Procedures of the Euroclear System, and applicable Belgian law (collectively, the “Terms and Conditions”). The Terms and Conditions govern transfers of securities and cash within Euroclear, withdrawals of securities and cash within Euroclear, withdrawals of

securities and cash from Euroclear, and receipts of payments with respect to securities in Euroclear. All securities in Euroclear are held on a fungible basis without attribution of specific certificates to specific securities clearance accounts. The Euroclear Operator acts under the Terms and Conditions only on behalf of Euroclear Participants and has no record of or relationship with persons holding through Euroclear Participants.

Distributions with respect to debt securities held beneficially through Euroclear will be credited to the cash accounts of Euroclear Participants in accordance with the Terms and Conditions, to the extent received by the U.S. depositary for Euroclear.

Clearstream advises that it is incorporated under the laws of Luxembourg as a professional depositary. Clearstream holds securities for its participating organizations (“Clearstream Participants”) and facilitates the clearance and settlement of securities transactions between Clearstream Participants through electronic book-entry changes in accounts of Clearstream Participants, thereby eliminating the need for physical movement of certificates. Clearstream provides to Clearstream Participants, among other things, services for safekeeping, administration, clearance, and settlement of internationally traded securities and securities lending and borrowing. Clearstream interfaces with domestic markets in several countries. As a professional depositary, Clearstream is subject to regulation by the Luxembourg Monetary Institute. Clearstream Participants are recognized financial institutions around the world, including agents, securities brokers and dealers, banks, trust companies, clearing corporations, and certain other organizations and may include any agents. Indirect access to Clearstream is also available to others, such as banks, brokers, dealers, and trust companies that clear through or maintain a custodial relationship with a Clearstream Participant either directly or indirectly.

Distributions with respect to debt securities held beneficially through Clearstream will be credited to cash accounts of Clearstream Participants in accordance with its rules and procedures, to the extent received by the U.S. depositary for Clearstream.

Secondary market trading between Euroclear participants and Clearstream participants will occur in the ordinary way in accordance with the applicable rules and operating procedures of Euroclear and Clearstream and will be settled using the procedures applicable to conventional eurobonds in immediately available funds.

Cross-market transfers between persons holding directly or indirectly through DTC, on the one hand, and directly or indirectly through Euroclear or Clearstream participants, on the other, will be effected within DTC in accordance with DTC’s rules on behalf of the relevant European international clearing system by its U.S. depositary; however, such cross-market transactions will require delivery of instructions to the relevant European international clearing system by the counterparty in such system in accordance with its rules and procedures and within its established deadlines (European time). The relevant European international clearing system will, if the transaction meets its settlement requirements, deliver instructions to its U.S. depositary to take action to effect final settlement on its behalf by delivering or receiving debt securities in DTC, and making or receiving payment in accordance with normal procedures. Euroclear participants and Clearstream participants may not deliver instructions directly to their respective U.S. depositaries.

Because of time-zone differences, credits of securities received in Euroclear or Clearstream as a result of a transaction with a DTC participant will be made during subsequent securities settlement processing and dated the business day following the DTC settlement date. Such credits, or any transactions in the debt securities settled during such processing, will be reported to the relevant Euroclear participants or Clearstream participants on that business day. Cash received in Euroclear or Clearstream as a result of sales of securities by or through a Euroclear participant or a Clearstream participant to a DTC participant will be received with value on the business day of settlement in DTC but will be available in the relevant Euroclear or Clearstream cash account only as of the business day following settlement in DTC.

Although DTC, Euroclear and Clearstream have agreed to the foregoing procedures in order to facilitate transfers of debt securities among participants of DTC, Euroclear and Clearstream, they are under no obligation to perform or continue to perform such procedures and they may discontinue the procedures at any time.

We have provided the descriptions herein of the operations and procedures of DTC, Euroclear and Clearstream solely as a matter of convenience. These operations and procedures are solely within the control of

DTC, Euroclear and Clearstream and are subject to change by them from time to time. Neither we, any underwriters nor the Trustee takes any responsibility for the accuracy of the information or these operations or procedures, and you are urged to contact DTC, Euroclear or Clearstream or their respective participants directly to discuss these matters.

We will be required to maintain an office or agency in each place of payment for each series of debt securities, for notice and demand purposes and for the purposes of presenting or surrendering debt securities for payment, registration of transfer, conversion or exchange.

If we act as our own paying agent with respect to any series of debt securities, on or before each due date of the principal of or any premium or interest on any of the debt securities of that series, we will be required to segregate and hold in trust for the benefit of the persons entitled to such payment a sum sufficient to pay the amount due until such sum is paid to such persons or otherwise disposed of as provided in the Indenture and to notify the Trustee promptly of our action or failure to act. If we have one or more paying agents for any series of debt securities, on each due date of the principal of or any premium or interest on any debt securities of that series, we will be required to deposit with a paying agent a sum sufficient to pay the amount due and, unless the paying agent is the Trustee, to promptly notify the Trustee of our action or failure to act. Subject to applicable escheat laws, any money deposited with a paying agent or the Trustee for the payment of principal of or any premium or interest on any debt securities that remains unclaimed for two years after the principal or any premium or interest has become due and payable may be repaid to us, and thereafter the holder of those debt securities may look only to us for payment thereof and all liability of the Trustee or any paying agent with respect to payment shall thereupon cease.

Subject to the transactions described under the heading “Consolidation, Merger, Sale, Conveyance, Transfer or Lease” below, we will be required to preserve and keep in full force and effect our corporate existence, charter rights, statutory rights, licenses and franchises, but the Company shall not be required to preserve any such right, license or franchise if the Company determines that such preservation is no longer desirable in the conduct of the business of the Company.

The Company will be required to furnish annually to the Trustee a certificate signed by one of its officers as to the officer’s knowledge of the Company’s compliance with all conditions and covenants under the Indenture.

The Company will not, in a single transaction or a series of related transactions, consolidate with or merge with or into, or sell, convey, transfer or lease all or substantially all of its properties and assets on a consolidated basis to, any person, unless:

Upon any consolidation of the Company with, or merger of the Company with or into, or any sale, conveyance, transfer or lease of all or substantially all of the properties and assets of the Company on a consolidated basis to, any person, in each case in accordance with the foregoing covenant, the Successor Company shall succeed to, and be substituted for, and may exercise every right and power of, the Company under the Indenture with the same effect as if the Successor Company had been named as the Company in the Indenture, and thereafter the predecessor Company shall be relieved of all obligations and covenants under the Indenture and the debt securities, except in the case of a lease of all or substantially all of the properties and assets of the Company on a consolidated basis, in which case the predecessor Company shall not be released from the obligation to pay the principal of, any premium on, and interest on the debt securities.

Unless otherwise indicated in the applicable prospectus supplement, the following are events of default under the Indenture with respect to debt securities of any series:

The Trustee is required to give to the holders of the debt securities of that series notice of all defaults known to a responsible officer of the Trustee within 90 days of the occurrence thereof, except that other than in the case of a default of the character contemplated in clause (1), (2), or (3) above, the Trustee may withhold notice if and so long as a committee of responsible officers of the Trustee in good faith determines that the withholding of notice is in the interests of the holders of the debt securities of that series.

If an event of default described in clause (5) above occurs, the principal of, premium, if any, and accrued interest on the debt securities of that series will become immediately due and payable automatically without any declaration or other action on the part of the Trustee or any holder of the debt securities of that series. If any other event of default with respect to debt securities of any series occurs and is continuing, either the Trustee or the holders of not less than 25% in principal amount of the outstanding debt securities of that series may declare

the principal amount of all debt securities of that series to be due and payable immediately. However, at any time after a declaration of acceleration with respect to debt securities of any series has been made, but before a judgment or decree based on such acceleration has been obtained, the holders of a majority in principal amount of the outstanding debt securities of that series may, under specified circumstances, rescind and annul such acceleration. See “—Amendments and Waivers” below.

Subject to the duty of the Trustee to act with the requisite standard of care during an event of default, the Trustee will be under no obligation to exercise any of the rights or powers under the Indenture at the request or direction of any holders of debt securities of any series unless such holders have offered to the Trustee security or indemnity reasonably satisfactory to it against the costs, losses, expenses and liabilities that might be incurred by it in compliance with such request or direction.

Except to enforce the right to receive payment of principal, premium, if any, or interest when due, no holder may institute any proceeding with respect to the Indenture unless:

Subject to certain restrictions, the holders of a majority in principal amount of the outstanding debt securities of any series are given the right to direct the time, method and place of conducting any proceeding for any remedy available to the Trustee or of exercising any trust or power conferred on the Trustee. The Indenture provides that in the event an event of default has occurred and is continuing, the Trustee will be required in the exercise of its rights and powers to use the degree of care and skill that a prudent person would exercise or use under the circumstances in the conduct of its own affairs. The Trustee, however, may refuse to follow any direction that conflicts with law or the Indenture or that the Trustee determines in good faith would involve the Trustee in personal liability. Prior to taking any action under the Indenture, the Trustee will be entitled to security or indemnification reasonably satisfactory to it against the costs, expenses and liabilities that might be incurred by it in compliance with any request or direction.

Any additional events of default with respect to any series of debt securities, and any variations from the foregoing events of default applicable to any series of debt securities, will be described in an applicable prospectus supplement.

An event of default for a particular series of debt securities does not necessarily constitute an event of default for any other series issued under the Indenture.

Subject to certain exceptions, the Indenture and the debt securities may be amended or supplemented with the consent of the holders of a majority in principal amount (including consents obtained in connection with a purchase of, or tender offer or exchange offer for, debt securities) of all debt securities at the time outstanding to be affected (considered together as one class for this purpose and such debt securities to be affected potentially being debt securities of the same or different series and, with respect to any series, potentially comprising fewer than all the debt securities of such series), or, if a waiver of compliance with provisions affects the debt securities of more than one series of debt securities, by the holders of a majority in principal amount of all outstanding debt securities affected by the waiver, with the debt securities of all the affected series voting together as one class for this purpose and such debt securities to be affected potentially being debt securities of the same or different series and, with respect to any series, potentially comprising fewer than all the debt securities of such series (including without limitation, consents obtained in connection with a purchase of, or

tender offer or exchange offer for, such series). Subject to certain exceptions, any past default may be waived with the consent of the holders of a majority in principal amount of the debt securities of such series then outstanding or, if the waiver of a past default affects the debt securities of more than one series of debt securities, by the holders of a majority in principal amount (including consents obtained in connection with a purchase of, or tender offer or exchange offer for, debt securities) of all debt securities at the time outstanding to be affected (considered together as one class for this purpose and such debt securities to be affected potentially being debt securities of the same or different series and, with respect to any series, potentially comprising fewer than all the debt securities of such series). In addition, without the consent of any holder, the Company and the Trustee may amend or supplement the Indenture or any series of debt securities for certain purposes as set forth in the Indenture.

However, without the consent of each holder of an outstanding debt security affected, no amendment, supplement or waiver may, among other things:

The consent of the holders is not necessary under the Indenture to approve the particular form of any proposed supplemental indenture. It is sufficient if such consent approves the substance of the proposed supplemental indenture. A consent to any amendment, supplement or waiver under the Indenture by any holder of debt securities given in connection with a purchase of, or tender or exchange offer for, such holder’s debt securities will not be rendered invalid by such purchase, tender or exchange.

The Company at any time may terminate all of its and any guarantor’s obligations under the debt securities of any series and the Indenture (“legal defeasance”), except for certain obligations, including those respecting the defeasance trust and obligations to register the transfer or exchange of such debt securities, to replace mutilated, destroyed, lost or stolen debt securities, and to maintain a registrar and paying agent in respect of the debt securities of any series and certain rights and immunities of the Trustee.

The Company may at any time terminate its and any guarantor’s obligations to comply with certain covenants described above under “—Certain Covenants” and certain covenants of any outstanding series of debt securities that may be contained in any applicable prospectus supplement, and may omit to comply with such

covenants without creating an event of default (“covenant defeasance”). The Company may exercise its legal defeasance option notwithstanding its prior exercise of its covenant defeasance option.

In order to exercise either defeasance option, the Company must irrevocably deposit in trust (the “defeasance trust”) with the Trustee money or U.S. government obligations, or a combination of money and U.S. government obligations, for the payment of principal, premium, if any, and interest on the debt securities of any series to redemption or maturity, as the case may be, and must comply with certain other conditions, including, without limitation, delivery to the Trustee of an opinion of counsel (subject to customary exceptions and exclusions) to the effect that holders of such series will not recognize gain or loss for Federal income tax purposes as a result of such deposit and defeasance and will be subject to Federal income tax on the same amount and in the same manner and at the same times as would have been the case if such deposit and defeasance had not occurred. In the case of legal defeasance only, such opinion of counsel must be based on a ruling of the Internal Revenue Service or other change in applicable Federal income tax law.

Upon the effectiveness of a legal defeasance or covenant defeasance with respect to any series of guaranteed debt securities, each guarantor of the debt securities of such series shall be automatically and unconditionally released and discharged from all of its obligations under its guarantee of the debt securities of such series and all of its other obligations under the Indenture in respect of the debt securities of that series, without any action by us, any guarantor or the Trustee, and without the consent of the holders of any debt securities.

The Indenture shall upon request of the Company cease to be of further effect with respect to the debt securities of any series and any guarantees of such debt securities (except as to any surviving rights of conversion, registration of transfer or exchange of any such debt security expressly provided for in the Indenture or in the terms of such debt security), and the Trustee, at the expense of the Company, shall execute proper instruments acknowledging satisfaction and discharge of the Indenture with respect to such debt securities, when:

Notwithstanding the satisfaction and discharge of the Indenture with respect to debt securities of any series, certain obligations of the Company and the Trustee listed in the Indenture shall survive such satisfaction and discharge.

We will pay interest, principal and other amounts payable with respect to the debt securities of any series to the holders of record of those debt securities as of the record dates and otherwise in the manner specified below or in the prospectus supplement for that series.

We will make payments on a global debt security in accordance with the applicable policies of the depositary as in effect from time to time. Under those policies, we will pay directly to the depositary, or its nominee, and not to any indirect owners who own beneficial interests in the global debt security. An indirect owner’s right to receive those payments will be governed by the rules and practices of the depositary and its participants.

We will make payments on a debt security in non-global, registered form as follows. We will pay interest that is due on an interest payment date by check mailed on the interest payment date to the holder at his or her address shown on the Trustee's records as of the close of business on the regular record date. We will make all other payments by check at the paying agent described below against surrender of the debt security. All payments by check will be made in next-day funds (i.e., funds that become available on the day after the check is cashed).

Alternatively, if a non-global debt security has a face amount of at least $1,000,000 and the holder asks us to do so, we will pay any amount that becomes due on the debt security by wire transfer of immediately available funds to an account at a bank in the United States of America, on the due date. To request wire payment, the holder must give the paying agent appropriate wire transfer instructions at least five business days before the requested wire payment is due. In the case of any interest payment due on an interest payment date, the instructions must be given by the person or entity who is the holder on the relevant regular record date. In the case of any other payment, payment will be made only after the debt security is surrendered to the paying agent. Any wire instructions, once properly given, will remain in effect unless and until new instructions are given in the manner described above.

Book-entry and other indirect owners should consult their banks or brokers for information on how they will receive payments on their debt securities.

No past, present or future director, officer, employee, manager, member, partner, incorporator or stockholder of the Company or any guarantor, as such, will have any liability for any obligations of the Company or any guarantor under the debt securities or the Indenture or for any claim based on, in respect of, or by reason of, such obligations or their creation. Each holder of debt securities by accepting a debt security waives and releases all such liability. The waiver and release are part of the consideration for issuance of the debt securities. The waiver may not be effective to waive liabilities under the federal securities laws.

The Base Indenture is, and each supplemental indenture and the debt securities will be, governed by, and construed in accordance with, the laws of the State of New York.

The Base Indenture provides that there may be more than one trustee under the Base Indenture, each with respect to one or more series of debt securities. If there are different trustees for different series of debt securities, each trustee will be a trustee of a trust under the Base Indenture separate and apart from the trust administered by any other trustee under the Base Indenture. Except as otherwise indicated in this prospectus or any prospectus supplement, any action permitted to be taken by a trustee may be taken by such trustee only with respect to the one or more series of debt securities for which it is the trustee under the Base Indenture. Any trustee under the Indenture may resign or be removed with respect to one or more series of debt securities. Except as provided above under the heading “Payments” or as otherwise provided in the applicable prospectus

supplement, all payments of principal of, premium, if any, and interest on, and all registration, transfer, exchange, authentication and delivery (including authentication and delivery on original issuance of the debt securities) of, the debt securities of a series will be effected by the trustee with respect to that series at an office designated by the trustee in the place of payment.

The Indenture does not prohibit the Trustee from serving as trustee under any other indenture to which we may be a party from time to time or from engaging in other transactions with us. If the Trustee acquires any conflicting interest within the meaning of the Trust Indenture Act and there is an event of default with respect to any series of debt securities, the Trustee must eliminate the conflict or resign.

The following is a description of (i) the material terms of our fourth amended and restated certificate of incorporation and second amended and restated bylaws and (ii) certain applicable provisions of Delaware law. We refer you to our fourth amended and restated certificate of incorporation and second amended and restated bylaws, copies of which are filed as exhibits to the registration statement of which this prospectus is a part.

Our authorized capital stock consists of 250,000,000 shares of common stock, par value $0.01 per share, and 50,000,000 shares of preferred stock, par value $0.01 per share.

As of July 31, 2022, 34,437,980 shares of our common stock were outstanding and no shares of our preferred stock were outstanding.

Holders of our common stock are entitled to the rights set forth below.

Holders of our common stock are entitled to one vote per share. Directors will be elected by a plurality of the votes cast by the holders of stock entitled to vote in the election. Our stockholders will not have cumulative voting rights. Except as otherwise provided in our fourth amended and restated certificate of incorporation or second amended and restated bylaws or as required by law, all matters to be voted on by our stockholders other than matters relating to the election and removal of directors must be approved by a majority of the shares present in person or by proxy at the meeting and entitled to vote on the subject matter or by a written resolution of the stockholders representing the number of affirmative votes required for such matter at a meeting.

Holders of common stock will share equally in any dividend declared by our Board, subject to the rights of the holders of any outstanding preferred stock.

In the event of any voluntary or involuntary liquidation, dissolution, distribution of assets, or winding up of our affairs, holders of our common stock would be entitled to share ratably in our assets that are legally available for distribution to stockholders after payment of liabilities. If we have any preferred stock outstanding at such time, holders of the preferred stock may be entitled to distribution and/or liquidation preferences. In either such case, we must pay the applicable distribution to the holders of our preferred stock before we may pay distributions to the holders of our common stock.

Our stockholders have no preemptive or other rights to subscribe for additional shares. All holders of our common stock are entitled to share equally on a share-for-share basis in any assets available for distribution to common stockholders upon our liquidation, dissolution or winding up. All outstanding shares are validly issued, fully paid and nonassessable.

Our Board is authorized to provide for the issuance of preferred stock in one or more series and to fix the designations, powers, rights and preferences of the shares of each such series, and qualifications, limitations and restrictions thereof, including voting rights, dividend rights, conversion rights, exchange rights, liquidation rights and redemption rights and to fix the number of shares to be included in any such series without any further vote or action by our stockholders. Any preferred stock so issued may rank senior to our common stock with respect to the payment of dividends or amounts upon liquidation, dissolution or winding up, or both. In addition, any such shares of preferred stock may have class or series voting rights. The issuance of preferred stock may have

the effect of delaying, deferring, or preventing a change in control of our company without further action by the stockholders and may adversely affect the voting and other rights of the holders of our common stock. Our Board has not authorized the issuance of any shares of preferred stock, and we have no agreements or plans for the issuance of any shares of preferred stock.

On August 15, 2016, we entered into a Warrant Agreement by and among us, Computershare, Inc. and Computershare Trust Company, N.A. (as amended, the “Warrant Agreement”). The Warrant Agreement governs the terms and rights of our warrants to purchase shares of common stock at the applicable exercise price of such warrants. Each warrant represents the right to purchase one share of common stock at an exercise price of $24.39 per share, subject to adjustment as provided in the Warrant Agreement. As of July 31, 2022, 9,432,064 warrants were outstanding and holders of such warrants are entitled to purchase, in the aggregate, up to 5,240,035 shares of common stock.

The warrants may be exercised in whole or in part at any time prior to the expiration time of 5:00 p.m. Pacific time on August 15, 2023. The warrants may be exercised upon delivery of a duly completed exercise notice on or prior to the expiration time at the offices of the warrant agent, accompanied by full payment of the exercise price for the number of warrants being exercised and a duly executed joinder to the Company’s Amended and Restated Stockholders Agreement.

No fractional shares will be issued upon the exercise of the warrants. If, upon exercise of the warrants, a holder would be entitled to receive a fractional interest in a share of common stock, we will, upon exercise, round down to the nearest whole number the number of shares of common stock to be issued to the warrant holder in accordance with the terms of the Warrant Agreement.

Each warrant not exercised prior to the expiration time shall become void, and all rights of the warrant holder under the Warrant Agreement shall cease. If a sale of the Company (as defined in the Warrant Agreement) is consummated prior to the expiration time in which 100% of the consideration paid to or received by non-employee holders of common stock in such sale of the Company consists of cash and the sale price is less than or equal to the exercise price on the date the sale of the Company is consummated, each warrant not exercised at or before that date shall also become void.

The warrant holders do not have the rights or privileges of holders of common stock including, without limitation, the right to vote or to consent or to receive notice as a stockholder in respect of any meeting of stockholders for the election of directors of the Company or any other matter, to receive dividends on warrant shares or any rights whatsoever as stockholders of the Company, until such warrant is duly exercised in accordance with the Warrant Agreement and such warrant holder is issued shares of common stock in connection therewith.

The warrants are transferable, provided that such transfer (i) would be permitted under the terms of our Amended and Restated Stockholders Agreement if such warrant constituted shares of common stock and (ii) is not made to a competitor without approval of our Board. The warrants are not transferable, however, if as a result of the transfer, the warrants would be held of record by 1,980 or more persons or 480 or more persons who are not “accredited investors”, or otherwise in circumstances that our Board determines would require us to file reports under the Exchange Act if we are not otherwise subject to such requirements.

The terms of the warrants may be amended, modified or waived by us together with the affirmative vote or consent of the majority holders of the warrants then outstanding; provided that if (i) the exercise price would be increased and/or the number of warrant shares would be decreased (other than pursuant to the adjustment) or

(ii) the expiration time is modified to occur earlier, then the consent of each warrant holder affected thereby is required. We and the warrant agent, however, may supplement or amend the Warrant Agreement as necessary without the approval of the warrant holders to cure any ambiguity or mistake so long as such amendment does not adversely affect, alter or change the interests of any warrant holder.

Our fourth amended and restated certificate of incorporation and second amended and restated bylaws contain provisions that delay, defer, or discourage transactions involving an actual or potential change in control of us or change in our management. These provisions, which are summarized below, discourage coercive takeover practices or inadequate takeover bids. These provisions are be designed to encourage persons seeking to acquire control of us to first negotiate with our Board, which we believe may result in an improvement of the terms of any such acquisition in favor of our stockholders. However, they also give our Board the power to discourage transactions that some stockholders may favor, including transactions in which stockholders might otherwise receive a premium for their shares or transactions that our stockholders might otherwise deem to be in their best interests. Accordingly, these provisions could adversely affect the price of our common stock.

Our fourth amended and restated certificate of incorporation provides that our Board will be divided into three classes, Class I, Class II and Class III, with members of each class serving staggered three-year terms. Our fourth amended and restated certificate of incorporation provides that the number of directors constituting the entire board may be changed only by the board of directors. Any additional directorships resulting from an increase in the number of directors will be distributed among the three classes so that, as nearly as possible, each class will consist of one-third of the directors. Our second amended and restated bylaws also provide that a director may be removed by the affirmative vote of the holders of a majority of our outstanding shares of capital stock entitled to vote generally in the election of directors, and only for cause. Any vacancy on our Board, including a vacancy resulting from an enlargement of our Board, may be filled only by the vote of a majority of our directors then in office. Our classified Board could have the effect of delaying or discouraging an acquisition of us or a change in our management.

Our second amended and restated bylaws provide that special meetings of the stockholders may be called upon the request of a majority of our Board, the Chairman of our Board and our Chief Executive Officer. Our second amended and restated bylaws prohibit the conduct of any business at a special meeting other than as specified in the notice for such meeting. These provisions may have the effect of deferring, delaying or discouraging hostile takeovers or changes in control or management of our company.

Our second amended and restated bylaws establish advance notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of our Board or a committee of our Board. In order for any matter to be “properly brought” before a meeting, a stockholder will have to comply with the advance notice requirements of directors, which may be filled only by a vote of a majority of directors then in office, even though less than a quorum, and not by the stockholders. Our second amended and restated bylaws allows the chairman of any meeting of stockholders to determine the order of business and the procedure at the meeting, including such regulation of the manner of voting and the conduct of discussion, which may have the effect of precluding the conduct of certain business at a meeting if the rules and regulations are not followed. These provisions may also defer, delay or discourage a potential acquirer from conducting a solicitation of proxies to elect the acquirer’s own slate of directors or otherwise attempting to obtain control of our company.

Our fourth amended and restated certificate of incorporation and our second amended and restated bylaws provide that subject to the rights of any holders of preferred stock to act by written consent instead of a meeting, stockholder action may be taken only at an annual meeting or special meeting of stockholders and may not be taken by written consent instead of a meeting. Failure to satisfy any of the requirements for a stockholder meeting could delay, prevent or invalidate stockholder action.

Our fourth amended and restated certificate of incorporation provides that the provisions of Section 203 of the DGCL, which relate to business combinations with interested stockholders, do not apply to us. Section 203 of the DGCL prohibits a publicly held Delaware corporation from engaging in a business combination transaction with an interested stockholder (a stockholder who owns more than 15% of our common stock) for a period of three years after the interested stockholder became such unless the transaction fits within an applicable exemption, such as Board approval of the business combination or the transaction that resulted in such stockholder becoming an interested stockholder. These provisions apply even if the business combination could be considered beneficial by some stockholders. Our fourth amended and restated certificate of incorporation contains provisions that have the same effect as Section 203 of the DGCL but provides that Mudrick Capital and any of its affiliates or successors, and any group as to which such persons are party do not constitute interested stockholders for purposes of these provisions for so long as they collectively own, directly or indirectly, 10% or more of the voting power of our then outstanding shares of voting stock. Although we have elected to opt out of the statute’s provisions, we could elect to be subject to Section 203 in the future.

Any amendment to our fourth amended and restated certificate of incorporation must first be approved by a majority of our Board and, if required by law, thereafter be approved by a majority of the outstanding shares entitled to vote on the amendment voting as a single class. Our second amended and restated bylaws may be amended (i) by the affirmative vote of a majority of the directors then in office, subject to any limitations set forth in the bylaws, without further stockholder action or (ii) by the affirmative vote of at least a majority of the outstanding shares entitled to vote on the amendment, voting as a single class, without further action by our Board.

Our fourth amended and restated certificate of incorporation provides that, we renounce any interest or expectancy in, or in being offered an opportunity to participate in, any business opportunity that may from time to time be presented to Mudrick Capital, Paulson or GoldenTree or any of their respective affiliates (including, but not limited to, any entity that, directly or indirectly, controls, is controlled by or is under common control with it and including, in the case of Paulson, any individual nominated by Paulson and appointed as a director of the Board as of the date of the fourth amended and restated certificate of incorporation), successors, directly or indirectly managed funds or vehicles, partners, principals, directors, officers, members, managers and employees (other than our company and its subsidiaries) (“Exempted Persons”), even if the opportunity is one that we might reasonably have pursued or had the ability or desire to pursue if granted the opportunity to do so. No such Exempted Persons will be liable to us for breach of any fiduciary or other duty, as a director or officer or otherwise, by reason of the fact that such person pursues or acquires any such business opportunity, directs any such business opportunity to another person or fails to present any such business opportunity, or information regarding any such business opportunity, to us. None of the Exempted Persons has any fiduciary duty to refrain from engaging directly or indirectly in the same or similar business activities or lines of business as us or any of our subsidiaries.

Our second amended and restated bylaws provide, subject to limited exceptions, that the Court of Chancery of the State of Delaware will, to the fullest extent permitted by law, be the sole and exclusive forum for (i) any derivative action or proceeding brought on our behalf; (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our directors, officers or other employees to us or our stockholders; (iii) any action asserting a claim against us, any director or our officers or employees arising pursuant to any provision of the DGCL, our fourth amended and restated certificate of incorporation or our second amended and restated bylaws; or (iv) any action asserting a claim against us, any director or our officers or employees that are governed by the internal affairs doctrine. This exclusive forum provision does not apply to claims arising under the Securities Act, the Exchange Act or other federal securities laws and rules and regulations promulgated thereunder for which there is exclusive federal or concurrent federal and state jurisdiction. The federal district courts of the United States of America shall be the sole and exclusive forum for the resolution of any action asserting a claim arising under the Securities Act, the Exchange Act or the rules and regulations promulgated thereunder, and investors

cannot waive compliance with the federal securities laws and the rules and regulations thereunder. Any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock shall be deemed to have notice of and to have consented to the provisions of our fourth amended and restated certificate of incorporation described above.

Our common stock is listed on Nasdaq under the symbol “THRY”.

The transfer agent and registrar for our common stock is Computershare Inc.

We may offer fractional interests in shares of preferred stock rather than full shares of preferred stock. In that event, depositary receipts will be issued to evidence depositary shares, each of which will represent a fraction of a share of a particular series of preferred stock, as described in the prospectus supplement relating to the particular issue of depositary shares.

The shares of preferred stock represented by depositary shares will be deposited under a deposit agreement between us and a depositary that is a bank or trust company, as depositary, that we select as set forth in the prospectus supplement relating to the particular issue of depositary shares. Unless otherwise specified in the prospectus supplement relating to a particular issue of depositary shares, each owner of a depositary share will be entitled, in proportion to the applicable fraction of a share of preferred stock represented by such depositary share, to all the rights and preferences of the shares of preferred stock represented by such depositary share, including dividend and liquidation rights and any right to convert the shares of preferred stock into common stock.

We will describe the terms of any depositary shares we offer and the related depositary agreement, as well as the terms of the shares of preferred stock represented thereby, in the prospectus supplement relating to the particular issue of depositary shares.

We may issue warrants that entitle the holder to purchase debt securities, preferred stock, common stock or depositary shares. Warrants may be issued independently or together with debt securities, preferred stock or common stock offered by any prospectus supplement and may be attached to or separate from any such offered securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and a bank or trust company, as warrant agent, all as will be set forth in the prospectus supplement relating to the particular issue of warrants. The warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any holders of warrants or beneficial owners of warrants.

The following summary of certain provisions of the warrants does not purport to be complete and is subject to, and is qualified in its entirety by reference to, all provisions of the warrant agreements.

Reference is made to the prospectus supplement relating to the particular issue of warrants offered pursuant to such prospectus supplement for the terms of and information relating to such warrants, including, where applicable:

Warrants issued pursuant to the registration statement of which this prospectus is a part will be issued in registered form only. The exercise price for warrants will be subject to adjustment in accordance with the applicable prospectus supplement.

Each warrant will entitle the holder thereof to purchase such principal amount of debt securities or such number of shares of preferred stock, common stock or depositary shares at such exercise price as shall in each case be set forth in, or calculable from, the prospectus supplement relating to the warrants, which exercise price may be subject to adjustment upon the occurrence of certain events as set forth in such prospectus supplement. After the close of business on the expiration date, or such later date to which such expiration date may be extended by us, unexercised warrants will become void. The place or places where, and the manner in which, warrants may be exercised shall be specified in the prospectus supplement relating to such warrants.

Prior to the exercise of any warrants to purchase debt securities, preferred stock, common stock or depositary shares, holders of such warrants will not have any of the rights of holders of such debt securities, preferred stock, common stock or depositary shares, as the case may be, purchasable upon such exercise, including the right to receive payments of principal of, premium, if any, or interest, if any, on the debt securities purchasable upon such exercise or to enforce covenants in the applicable indenture, or to receive payments of dividends, if any, on the preferred stock, or common stock purchasable upon such exercise, or to exercise any applicable right to vote or to exercise any rights of holders of depositary receipts in respect of the depositary shares purchasable upon such exercise.

We may issue, in one or more series, units consisting of debt securities, common stock, preferred stock, and/or warrants for the purchase of debt securities, preferred stock, common stock or depositary shares in any combination. We urge you to read the applicable prospectus supplement and any free writing prospectus that we may authorize to be provided to you related to the series of units being offered, as well as the complete unit agreement that contains the terms of the units. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of unit agreement and any supplemental agreements that describe the terms of the series of units we are offering before the issuance of the related series of units.

We will evidence each series of units by unit certificates that we will issue. Units may be issued under a unit agreement that we enter into with a unit agent. We will indicate the name and address of the unit agent, if applicable, in the prospectus supplement relating to the particular series of units being offered.

We may sell the offered securities in and outside the United States (1) through underwriters or dealers; (2) directly to purchasers, including our affiliates and shareholders, or in a rights offering; (3) through agents (acting as agent or principal); (4) through a combination of any of these methods; or (5) through any other method described in a prospectus supplement. The prospectus supplement will include the following information:

We may engage in at-the-market offerings into an existing trading market in accordance with Rule 415(a)(4) under the Securities Act. In addition, we may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third parties may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third parties in such sale transactions will be underwriters and, if not identified in this prospectus, will be identified in the applicable prospectus supplement (or a post-effective amendment). We or one of our affiliates may loan or pledge securities to a financial institution or other third party that in turn may sell the securities using this prospectus. Such financial institution or third party may transfer its short position to investors in our securities or in connection with a simultaneous offering of other securities offered by this prospectus or otherwise.

If we use underwriters in the sale, the underwriters will acquire the securities for their own account for resale to the public. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless we inform you otherwise in the prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to certain conditions, and the underwriters will be obligated to purchase all of the offered securities if they purchase any of them. The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers.

Representatives of the underwriters through whom the offered securities are sold for public offering and sale may engage in over-allotment, stabilizing transactions, syndicate short covering transactions and penalty bids in accordance with Regulation M under the Exchange Act. Over-allotment involves syndicate sales in excess of the offering size, which creates a syndicate short position. Stabilizing transactions permit bids to purchase the offered securities so long as the stabilizing bids do not exceed a specified maximum. Syndicate covering transactions involve purchases of the offered securities in the open market after the distribution has been completed in order to cover syndicate short positions. Penalty bids permit the representative of the underwriters to reclaim a selling concession from a syndicate member when the offered securities originally sold by such syndicate member are purchased in a syndicate covering transaction to cover syndicate short positions. Such stabilizing transactions, syndicate covering transactions and penalty bids may cause the price of the offered securities to be higher than it would otherwise be in the absence of such transactions. These transactions may be effected on a national securities exchange and, if commenced, may be discontinued at any time.

Some or all of the securities that we offer through this prospectus may be new issues of securities with no established trading market. Any underwriters to whom we sell our securities for public offering and sale may make a market in those securities, but they will not be obligated to do so and they may discontinue any market making at any time without notice. Accordingly, we cannot assure you of the liquidity of, or continued trading markets for, any securities that we offer.

If we use dealers in the sale of securities, we will sell the securities to them as principals. They may then resell those securities to the public at varying prices determined by the dealers at the time of resale. If applicable, we will include in the prospectus supplement the names of the dealers and the terms of the transaction.

We may sell the securities directly. In this case, no underwriters or agents would be involved. We may also sell the securities through agents designated from time to time. In the prospectus supplement, we will name any agent involved in the offer or sale of the offered securities, and we will describe any commissions payable to the agent. Unless we inform you otherwise in the prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

We may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. We will describe the terms of any such sales in the prospectus supplement.

We may also make direct sales through subscription rights distributed to our existing stockholders on a pro rata basis that may or may not be transferable. In any distribution of subscription rights to our stockholders, if all of the underlying securities are not subscribed for, we may then sell the unsubscribed securities directly to third parties or we may engage the services of one or more underwriters, dealers or agents, including standby underwriters, to sell the unsubscribed securities to third parties.

Offered securities also may be offered and sold, if so indicated in the applicable prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more remarketing firms, acting as principals for their own accounts or as agents for us. Any remarketing firm will be identified and the terms of its agreements, if any, with us and its compensation will be described in the applicable prospectus supplement. Remarketing firms may be deemed to be underwriters, as that term is defined in the Securities Act, in connection with the securities remarketed.

If we so indicate in the prospectus supplement, we may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase securities from us at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in the prospectus supplement. The prospectus supplement will describe the commission payable for solicitation of those contracts.

We may have agreements with the underwriters, dealers and agents to indemnify them against certain civil liabilities, including liabilities under the Securities Act, or to contribute with respect to payments that the underwriters, dealers or agents may be required to make.

Underwriters, dealers and agents may engage in transactions with, or perform services for, us in the ordinary course of our business for which they may receive compensation.

The validity of the securities being offered by this prospectus will be passed upon for us by Akin Gump Strauss Hauer & Feld LLP, Dallas, Texas, our outside legal counsel. Additional legal matters may be passed on for us, or any underwriters, dealers or agents, by counsel we will name in the applicable prospectus supplement.

The consolidated financial statements of Thryv Holdings, Inc. and Subsidiaries appearing in Thryv Holdings, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2021, and the effectiveness of Thryv Holdings, Inc. and Subsidiaries’ internal control over financial reporting as of December 31, 2021 (excluding the internal control over financial reporting of Thryv Australia), have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, which as to the report on the effectiveness of Thryv Holdings, Inc. and Subsidiaries’ internal control over financial reporting contains an explanatory paragraph describing the above referenced exclusion of Thryv Australia from the scope of such firm's audit of internal control over financial reporting, included therein, and incorporated herein by reference. Such financial statements are, and audited financial statements to be included in subsequently filed documents will be, incorporated herein in reliance upon the reports of Ernst & Young LLP pertaining to such financial statements and the effectiveness of our internal control over financial reporting as of the respective dates (to the extent covered by consents filed with the Securities and Exchange Commission) given on the authority of such firm as experts in accounting and auditing.

The consolidated financial statements of Sensis Holding Limited at June 30, 2020 and 2019, and for each of the two years in the period ended June 30, 2020, incorporated by reference in this prospectus and registration statement have been audited by Ernst & Young LLP, independent auditors, as set forth in their report incorporated by reference herein, and are included in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

The following table sets forth the expenses (all of which are estimated) to be borne by us in connection with a distribution of securities registered under this Registration Statement.

We are governed by the Delaware General Corporation Law, or DGCL. Section 145 of the DGCL provides that a corporation may indemnify any person, including an officer or director, who was or is, or is threatened to be made, a party to any threatened, pending or completed legal action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of such corporation), by reason of the fact that such person was or is an officer, director, employee or agent of such corporation or is or was serving at the request of such corporation as a director, officer, employee or agent of another corporation or enterprise. The indemnity may include expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with such action, suit or proceeding, provided such officer, director, employee or agent acted in good faith and in a manner such person reasonably believed to be in, or not opposed to, the corporation’s best interest and, for criminal proceedings, had no reasonable cause to believe that such person’s conduct was unlawful. A Delaware corporation may indemnify any person, including an officer or director, who was or is, or is threatened to be made, a party to any threatened, pending or contemplated action or suit by or in the right of such corporation, under the same conditions, except that such indemnification is limited to expenses (including attorneys’ fees) actually and reasonably incurred by such person, and except that no indemnification is permitted without judicial approval if such person is adjudged to be liable to such corporation. Where an officer or director of a corporation is successful, on the merits or otherwise, in the defense of any action, suit or proceeding referred to above, or any claim, issue or matter therein, the corporation must indemnify that person against the expenses (including attorneys’ fees) which such officer or director actually and reasonably incurred in connection therewith.

Our second amended and restated bylaws authorizes the indemnification of our officers and directors, consistent with Section 145 of the DGCL, as amended. We have entered into indemnification agreements with each of our directors and executive officers. These agreements, among other things, require us to indemnify each director and executive officer to the fullest extent permitted by Delaware law, including indemnification of expenses such as attorneys’ fees, judgments, fines and settlement amounts incurred by the director or executive officer in any action or proceeding, including any action or proceeding by or in right of the company, arising out of the person’s services as a director or executive officer.

Further, we have entered into indemnification agreements with each of our directors and executive officers that may be broader than the specific indemnification provisions contained in the Delaware General Corporation Law. These indemnification agreements require us, among other things, to indemnify our directors and executive officers against liabilities that may arise by reason of their status or service. These indemnification agreements

also require us to advance all expenses incurred by the directors and executive officers in investigating or defending any such action, suit or proceeding. We believes that these agreements are necessary to attract and retain qualified individuals to serve as directors and executive officers.

Reference is made to Section 102(b)(7) of the DGCL, which enables a corporation in its original certificate of incorporation or an amendment thereto to eliminate or limit the personal liability of a director for violations of the director’s fiduciary duty, except (i) for any breach of the director’s duty of loyalty to the corporation or its stockholders, (ii) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (iii) pursuant to Section 174 of the DGCL, which provides for liability of directors for unlawful payments of dividends of unlawful stock purchase or redemptions or (iv) for any transaction from which a director derived an improper personal benefit.

We expect to maintain standard policies of insurance that provide coverage (i) to our directors and officers against loss rising from claims made by reason of breach of duty or other wrongful act and (ii) to us with respect to indemnification payments that we may make to such directors and officers.

Each undersigned registrant hereby undertakes:

1. To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) to include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii) to reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Securities and Exchange Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement;

(iii) to include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

Provided, however, that paragraphs (i), (ii) and (iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Securities and Exchange Commission by the Registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

2. That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

3. To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

4. That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

(i) Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

5. That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a

primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser: (i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424; (ii) any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant; (iii) the portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and (iv) any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

6. The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

7. Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933 and is therefore unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933, and will be governed by the final adjudication of such issue.

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believe that it meets all of the filing requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Dallas, State of Texas, on August 4, 2022.

KNOW ALL MEN BY THESE PRESENTS, that each of the undersigned hereby constitutes and appoints Paul D. Rouse and Lesley Bolger, each of whom may act without joinder of the other, as their true and lawful attorney in fact and agent, with full power of substitution, for such person and on his or her behalf and in his or her name, place and stead, in any and all capacities, to sign, execute and file this registration statement under the Securities Act of 1933, as amended, and any or all amendments (including, without limitation, post effective amendments), with all exhibits and any and all documents required to be filed with respect thereto, with the Securities and Exchange Commission or any regulatory authority, granting unto such attorney in fact and agent, full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises in order to effectuate the same, as fully to all intents and purposes as he himself or her herself might or could do, if personally present, hereby ratifying and confirming all that said attorney in fact and agent, or his or her substitute or substitutes, may lawfully do or cause to be done.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities indicated below on August 4, 2022.