UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K/A

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): June 17, 2013

General Motors Financial Company, Inc.

(Exact name of registrant as specified in its charter)

801 Cherry Street, Suite 3500, Fort Worth, Texas 76102

(Address of principal executive offices, including Zip Code)

(817) 302-7000

(Registrant’s telephone number, including area code)

(Not Applicable)

(Former name or former address, if changed since last report)

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:

This Amendment No. 1 to Form 8-K (“Amendment No. 1”) is being filed to amend the current report on Form 8-K (the “Initial 8-K”) filed with the Securities and Exchange Commission on April 5, 2013, by General Motors Financial Company, Inc. (“GM Financial” or the “Company”), which was filed to report that the Company had completed a transaction under which it acquired Ally Financial Inc.’s (“Ally”) equity interests in Ally’s top-level holding companies that comprise substantially all of Ally’s auto finance and financial services business in Europe, other than in France and Portugal, and in Latin America, other than Brazil. This Amendment No. 1 is being filed to provide the required historical financial statements and unaudited pro forma financial information not required to be included in the Initial 8-K.

Forward-Looking Statements

Except for the historical information contained herein, the matters disclosed herein include forward-looking statements which are the Company’s current views with respect to future events and financial performance. These forward-looking statements are subject to many assumptions, risks and uncertainties that could cause actual results to differ significantly from historical results or those anticipated by the Company. The most significant of these risks are detailed from time to time in the Company’s filings and reports with the Securities and Exchange Commission including the Company’s annual report on Form 10-K for the year ended December 31, 2012. If one or more of these risks or uncertainties materializes, or if underlying assumptions prove incorrect, the Company’s actual results may vary materially from those expected, estimated or projected. Actual events or results may differ materially. It is advisable not to place undue reliance on any forward-looking statements. The Company undertakes no obligation to, and does not, publicly update or revise any forward-looking statements, except as required by federal securities laws, whether as a result of new information, future events or otherwise.

The following financial statements for the international auto finance and financial services businesses of Ally (“Ally-IO”) are filed as Exhibit 99.1 hereto and incorporated by reference herein: audited combined balance sheets of Ally-IO as of December 31, 2012 and 2011, and the related combined statements of comprehensive income, changes in invested equity, and cash flows for each of the three years ended December 31, 2012, and the report of the independent registered public accounting firm related thereto.

The pro forma financial information reflecting the acquisition of the international auto finance and financial services businesses of Ally in Europe, other than France and Portugal, and in Latin America, other than Brazil, is hereby incorporated by reference to Exhibit 99.2 hereto.

SIGNATURES

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

INDEX TO EXHIBITS