1225 Form 1120-X (PDF)

Official source: IRS Forms, Instructions & Publications (https://www.irs.gov/pub/irs-pdf/f1120x.pdf), retrieved 2026-10-03. U.S. Government work (17 U.S.C. § 105).

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Form

(Rev. December 2025)

Department of the Treasury Internal Revenue Service Go to www.irs.gov/Form1120X for instructions and the latest information.

OMB No. 1545-0123

For tax year ending

(Enter month and year.)

Name Employer identification number

Number and street. If a P.O. box, see instructions. Room or suite number

City or town State/Province Country ZIP/foreign code Telephone number (optional)

Enter name and address used on original return. If same as above, write “Same.”

Internal Revenue Service Center where original return was filed

A Is the corporation making an election under Regulations section 301.9100? . . . . . . . . . . . Yes No If “Yes,” identify the election the corporation is making by filing this Form 1120-X:

If “Yes,” identify the election the corporation is making by filing this Form 1120-X:

Fill in applicable items and use Part II on the back to explain any changes.

Payments and Credits (see instructions)

5a Overpayment in prior year allowed as a credit . . . 5a b Estimated tax payments . . . . . . . . . . 5b c Refund applied for on Form 4466 . . . . . . . 5c d Subtract line 5c from the sum of lines 5a and 5b . . 5d e Tax deposited with Form 7004 . . . . . . . . 5e f Credit from Form 2439 . . . . . . . . . . 5f g Credit for federal tax on fuels and other refundable

credits or similar items . . . . . . . . . . 5g 6 Tax deposited or paid with (or after) the filing of the original return . . . . . . . . . . . 6 7 Add lines 5d through 6, column (c) . . . . . . . . . . . . . . . . . . . . . 7 8 Overpayment, if any, as shown on original return or as later adjusted . . . . . . . . . . 8 9 Subtract line 8 from line 7 . . . . . . . . . . . . . . . . . . . . . . . . 9

Tax Due or Overpayment (see instructions)

Form 1120-X (Rev. 12-2025) Page 2 Part II Explanation of Changes to Items in Part I (Enter the line number from Part I for the items you are changing, and give the reason for each change. Show any computation in detail. Also, see What To Attach in the instructions.) If the change is due to a net operating loss carryback, a capital loss carryback, or a general business credit carryback, see Carryback Claims in the instructions, and check here . . . . . . . . . . . . . . . . . . . . . . . .

Form 1120-X (Rev. 12-2025)