UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): October 28, 2010

SYNIVERSE HOLDINGS, INC.

SYNIVERSE TECHNOLOGIES, INC.

(Exact name of registrant as specified in its charter)

8125 Highwoods Palm Way

Tampa, Florida 33647

Telephone: (813) 637-5000

(Address, including zip code, and telephone number, including area code, of registrants’ principal executive offices)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

On October 28, 2010, Syniverse Holdings, Inc., a Delaware corporation (the “Company”), entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Buccaneer Holdings, Inc., a Delaware corporation (“Parent”), and Buccaneer Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Parent (“Merger Sub”), providing for the merger of Merger Sub with and into the Company (the “Merger”), with the Company surviving the Merger as a wholly owned subsidiary of Parent. Parent and Merger Sub are affiliates of Carlyle Partners V, L.P. (“Carlyle”). The Merger Agreement was unanimously approved by the Company’s Board of Directors.

At the effective time of the Merger, each share of Company common stock issued and outstanding immediately prior to the effective time (other than (i) shares held by the Company in treasury, (ii) owned directly or indirectly, by any of the Company’s wholly owned subsidiaries, Parent, or Merger Sub or any other direct or indirect wholly owned subsidiary of Parent, or (iii) held by stockholders who have perfected and not withdrawn a demand for appraisal rights under Delaware law) will be automatically cancelled and converted into the right to receive $31.00 in cash (the “Per Share Merger Consideration”), without interest.

Consummation of the Merger is subject to customary conditions, including without limitation (i) the approval by the holders of a majority of the outstanding shares of the Company’s common stock entitled to vote on the Merger, (ii) the expiration or early termination of the waiting period applicable to the consummation of the Merger under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and the receipt of certain foreign antitrust approvals, and (iii) consent by the Federal Communications Commission (“FCC”) to the transfer of control of the Company and its subsidiaries.

Parent and Merger Sub have obtained equity and debt financing commitments for the transaction contemplated by the Merger Agreement, the aggregate proceeds of which will be sufficient for Parent to finance the transactions contemplated by the Merger Agreement, including payment of the aggregate Per Share Merger Consideration and all related fees and expenses. Carlyle has agreed to guarantee certain obligations of Parent under the Merger Agreement, on the terms and subject to the conditions set forth in a limited guarantee in favor of the Company dated October 28, 2010 (the “Limited Guarantee”), including the payment of certain monetary obligations that may be owed by Parent pursuant to the Merger Agreement, including any termination fee that may become payable by Parent.

The Company is subject to customary “no-shop” restrictions on its ability to solicit alternative acquisition proposals from third parties and to provide information to and engage in discussions with third parties regarding alternative acquisition proposals. However, prior to approval of the Merger by the Company’s stockholders, the no-shop provision is subject to a customary “fiduciary-out” provision which allows the Company under certain circumstances, and subject to certain conditions, to provide information to and participate in discussions with third parties with respect to certain unsolicited alternative acquisition proposals that the Board of Directors has determined would, if consummated, result in a transaction more favorable to the Company’s stockholders from a financial point of view than the transaction contemplated by the Merger Agreement and is reasonably likely to be completed on the terms proposed on a timely basis.

The Merger Agreement contains certain termination rights for the Company and Parent. Upon termination of the Merger Agreement under specified circumstances, the parties may be required to pay the other party a termination fee. If the Company is required to pay a termination fee as a result of the Company entering into an alternative acquisition agreement or making an adverse

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change in its recommendation of the Merger, the amount of the termination fee is $60.0 million. The Merger Agreement also provides that Parent will be required to pay the Company a termination fee of $60 million if Parent fails to receive the requisite foreign antitrust or FCC approvals under certain circumstances and $120 million if the Merger Agreement is terminated under certain circumstances because Parent fails to complete the Merger or otherwise breaches its obligations under the Merger Agreement.

The representations, warranties and covenants of the Company contained in the Merger Agreement have been made solely for the benefit of Parent and Merger Sub. In addition, such representations, warranties and covenants (a) have been made only for purposes of the Merger Agreement, (b) have been qualified by confidential disclosures made to Parent and Merger Sub in connection with the Merger Agreement, (c) are subject to materiality qualifications contained in the Merger Agreement which may differ from what may be viewed as material by investors, (d) were made only as of the date of the Merger Agreement or such other date as is specified in the Merger Agreement, and (e) have been included in the Merger Agreement for the purpose of allocating risk between the contracting parties rather than establishing matters as facts. Accordingly, the Merger Agreement is included with this filing only to provide investors with information regarding the terms of the Merger Agreement, and not to provide investors with any other factual information regarding the Company or its business. Investors should not rely on the representations, warranties and covenants or any descriptions thereof as characterizations of the actual state of facts or condition of the Company or any of its subsidiaries or affiliates. Moreover, information concerning the subject matter of the representations and warranties may change after the date of the Merger Agreement, which subsequent information may or may not be fully reflected in the Company’s public disclosures. The Merger Agreement should not be read alone, but should instead be read in conjunction with the other information regarding the Company that is or will be contained in, or incorporated by reference into, the Forms 10-K, Forms 10-Q and other documents that the Company files or has filed with the SEC.

The foregoing description of the Merger Agreement and the transactions contemplated thereby does not purport to be complete and is subject to, and qualified in its entirety by, the full text of the Merger Agreement attached hereto as Exhibit 2.1, which is incorporated herein by reference.

On October 29, 2010, the Company’s Chief Executive Officer addressed all of the Company’s employees via a video posted on the Company’s internal website. A transcript of this video is filed as Exhibit 99.1 hereto.

Forward-Looking Statements

We have made forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), in this report. The words “believes,” “anticipates,” “plans,” “expects,” “intends,” “estimates,” “seeks,” “may” and similar expressions are intended to identify forward-looking statements. These forward-looking statements involve known and unknown risks, uncertainties and other factors that could cause our actual results, performance and achievements, to differ materially from any future results, performance or achievements expressed or implied by such forward-looking statements. Certain factors that could cause actual events not to occur as expressed in the forward-looking statement include among others: the occurrence of any event, change or other circumstances that could give rise to the termination of the merger agreement; the outcome of any legal proceedings that have been, or will be, instituted against the Company related to the merger agreement; the inability to complete the merger due to the failure to obtain stockholder approval for the merger or the failure to satisfy other conditions to completion of the merger, including the receipt of all regulatory approvals related to the merger; the failure to obtain the necessary financing arrangements set forth in the debt and equity commitment letters delivered pursuant to the merger agreement; risks that the proposed transaction disrupts current plans and operations and the potential difficulties in employee retention as a result of the merger;

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the impact of the substantial indebtedness to be incurred to finance the consummation of the merger; the effects of local and national economic, credit and capital market conditions on the economy in general, and other risks and uncertainties described herein, as well as those risks and uncertainties discussed from time to time in our other reports and other public filings with the Securities and Exchange Commission (the “SEC”).

Although we presently believe that the plans, expectations and results expressed in or suggested by the forward-looking statements are reasonable, all forward-looking statements are inherently subjective, uncertain and subject to change, as they involve substantial risks and uncertainties beyond our control. New factors emerge from time to time, and it is not possible for us to predict the nature, or assess the potential impact, of each new factor on our business. Given these uncertainties, we caution you not to place undue reliance on these forward-looking statements. We undertake no obligation to update or revise any of our forward-looking statements for events or circumstances that arise after the statement is made, except as otherwise may be required by law. This list of risks and uncertainties, however, is only a summary of some of the most important factors and is not intended to be exhaustive. Additional information regarding risk factors that may affect us is included under the caption “Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2009.

Additional Information and Where to Find It

In connection with the proposed merger, Syniverse Holdings, Inc. (the “Company”) will prepare a proxy statement to be filed with the SEC. When completed, a definitive proxy statement and a form of proxy will be mailed to the stockholders of the Company. THE COMPANY’S SECURITY HOLDERS ARE URGED TO READ THE PROXY STATEMENT REGARDING THE PROPOSED MERGER BECAUSE IT WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED MERGER. The Company’s stockholders will be able to obtain, without charge, a copy of the proxy statement (when available) and other relevant documents filed with the SEC from the SEC’s website at http://www.sec.gov. The Company’s stockholders will also be able to obtain, without charge, a copy of the proxy statement and other relevant documents (when available) by directing a request by mail or telephone to Syniverse Holdings, Inc., 8125 Highwoods Palm Way, Tampa, Florida 33647, attn: Corporate Secretary, or from the Company’s website, http://www.syniverse.com.

The Company and its directors and officers may be deemed to be participants in the solicitation of proxies from the Company’s stockholders with respect to the special meeting of stockholders that will be held to consider the proposed merger. Information about the Company’s directors and executive officers and their ownership of the Company’s common stock is set forth in the proxy statement for the Company’s 2010 Annual Meeting of stockholders, which was filed with the SEC on April 5, 2010. Stockholders may obtain additional information regarding the interests of the Company and its directors and executive officers in the proposed merger, which may be different than those of the Company’s stockholders generally, by reading the proxy statement and other relevant documents regarding the proposed merger, when filed with the SEC.

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(d) Exhibits.

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SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

Dated: October 29, 2010

EXHIBIT INDEX

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