In general. Any corporation which has made an overpayment of estimated income tax for a taxable year beginning after December 31, 1967, may file an application for an adjustment of such overpayment. The right to file an application for an adjustment of overpayment of estimated income tax is limited to corporations.

Contents of application. (1) The application for an adjustment of overpayment of estimated income tax shall be filed on Form 4466. The application shall be filled out in accordance with the instructions accompanying the form, and all information required by the form and instructions must be furnished by the corporation. The application shall be verified in the manner prescribed by section 6065 as in the case of a return of the corporation.

An application for an adjustment of overpayment of estimated income tax does not constitute a claim for credit or refund. If such application is disallowed by the district director, or director of a service center, in whole or in part, no suit may be maintained in any court for the recovery of any tax based on such application. The filing of an application for an adjustment of overpayment of estimated income tax will not constitute the filing of a claim for credit or refund within the meaning of section 6511 for the purpose of determining whether a claim for refund was filed prior to the expiration of the applicable period of limitation. The corporation, however, may file a claim for credit or refund under section 6402 at any time prior to the expiration of the applicable period of limitation and may maintain a suit based on such claim if it is disallowed or if the district director, or director of a service center, does not act on the claim within 6 months from the date it is filed. Such claim may be filed before, simultaneously with, or after the filing of the application for the adjustment of overpayment of estimated tax. A claim for credit or refund under section 6402 filed after the filing of an application for an adjustment of overpayment of estimated income tax is not to be considered an amendment of such application. Such claim, however, in proper cases, may constitute an amendment to a prior claim filed under section 6402.

Time and place for filing application. (1) The application for an adjustment of overpayment of estimated income tax shall be filed after the last day of the taxable year and on or before the 15th day of the third month thereafter, or before the date on which the corporation first files its income tax return for such taxable year (whether or not it subsequently amends the return), whichever is earlier.

Except as provided in paragraph (b)(2) of § 301.6091-1 of this chapter (relating to hand-carried documents), the application on Form 4466 shall be filed with the internal revenue officer designated in instructions applicable to such form.