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CAUTION

Include on line 6 the amount you reported on Schedule 2 (Form 1040), line 3, for the year you are amending.

Figure the tax on your taxable income shown on line 5, column C. Generally, you will use the method(s) you used to figure the tax on your original return. However, you may need to change to a different method if, for example, you amend your return to include or change the amount of certain types of income, such as capital gains or qualified dividends.

See the instructions for the income tax return you are amending to find the appropriate method(s), tax table, and worksheet, if necessary. Indicate the method(s) you used to figure the tax entered on line 6, as shown in the chart below.

TIP

Schedule 1-A and these deductions were introduced in 2025.

8 Instructions for Form 1040-X (Rev. December 2025)

If you made any changes to Form 1040-X, lines 1 through 6, be sure to refigure your original credits. Attach the appropriate forms for the credits you are adding or changing.

Credit for qualifying children and other dependents. If you are amending a return with a retroactive claim of the child tax credit, you must have an SSN valid for employment issued for the child before the due date for filing the return you are amending, including extensions. If you are amending a return with a retroactive claim of the credit for other dependents, the dependent you claim must have been issued an SSN, ITIN, or adoption taxpayer identification number (ATIN) on or before the due date for filing the return you are amending, including extensions. Your child tax credit may be refundable. For additional information, see Schedule 8812 (Form 1040) and its instructions for the year of the tax return you are amending.

Line 9—Reserved for Future Use

This line is reserved for future use. Do not enter an amount on this line.

Line 10—Other Taxes

Enter in column A the amount you reported on the line for total other taxes from Schedule 2 (Form 1040) for the year you are amending.

If you made any changes to Form 1040-X, lines 1 through 6, you may need to refigure other taxes that were included in the same section on your original return.

Payments

Line 12—Withholding

In column A, enter from the return you are amending any federal income tax withheld and any excess social security and tier 1 RRTA tax withheld (SS/RRTA).

If you are changing your withholding or excess SS/RRTA, attach to the front of Form 1040-X a copy of all additional or corrected Forms W-2 you received after you filed your original return. Also attach additional or corrected Forms 1099-R that show any federal income tax withheld.

Line 13—Estimated Tax Payments

In column A, enter the estimated tax payments you claimed on your original return. If you filed Form 1040-C, U.S. Departing Alien Income Tax Return, include on this line the amount you paid as the balance due with that return. Also include any of your prior year's overpayment that you elected to apply to estimated tax payments for the year you are amending.

Line 14—Earned Income Credit (EIC)

Enter the amount you reported on the line for the EIC on Form 1040 or 1040-SR for the year you are amending in column A. If you are amending your return to claim the EIC and you have a qualifying child, attach Schedule EIC (Form 1040). If you changed the amount on line 1 or line 5, the amount of any EIC you claimed on your original return may change. For more information regarding the EIC, see Pub. 596 for the year you are amending.

If you are amending your EIC based on a nontaxable combat pay election, enter “nontaxable combat pay” and the amount in Part II of Form 1040-X.

SSN required. If you didn't have an SSN on or before the due date of your return for the tax year being amended (including extensions), you can't claim the EIC on your amended return. Also, if a child didn't have an SSN on or before the due date of your return for the tax year being amended (including extensions), you can't count that child as a qualifying child in figuring the amount of the EIC on your amended return.

Line 15—Refundable Credits

A refundable credit can give you a refund for any part of a credit that is more than your total tax. Enter, in column A, the total of the refundable credits from Schedule 8812 (Form 1040), Form 8863, the recovery rebate (as applicable), and Schedule 3 (Form 1040) for the year you are amending. Check as applicable the boxes for Schedule 8812 (Form 1040), and Forms 2439, 4136, 8885, 8863, and 8962.

If you are amending your return to claim or change a refundable credit, attach the appropriate schedule(s) or form(s).

In addition, in the blank area after “other (specify),” list all of your refundable credits for which there is not a checkbox. Include the form number for the credit if there is one.

SSN required. If you are amending a return with a retroactive claim of the refundable child tax credit or the additional child tax credit, you must have an SSN valid for employment issued for the child before the due date for filing the return, including extensions. For additional information, see Schedule 8812 (Form 1040) and its instructions for the year of the tax return you are amending.

Line 16—Amount Paid With Extension or Tax Return

On this line, enter the total of the following amounts.

• Any amount paid with your request for an extension on Form 4868, Application for Automatic Extension of Time To File U.S. Individual Income Tax Return; or Form 2350, Application for Extension of Time To File U.S. Income Tax Return. Also include any amount paid electronically in connection with an extension of time to file, but don’t include the convenience fee you were charged.

• The amount you paid with your original return, regardless of method. Also include any additional payments you made after it was filed. However, don’t include payments of interest or penalties, or the convenience fee you were charged.

Example. You are filing Form 1040-X to amend your 2024 tax return. You sent a check for $1,500 with your original return, reflecting a payment of $1,400 in taxes and a $100 estimated tax penalty. When completing Form 1040-X, enter $1,400 on line 16 (the check sent with the original return minus the $100 penalty).

Line 17—Total Payments

Include any amounts from Form 8689, Allocation of Individual Income Tax to the U.S. Virgin Islands, that are being included in the total payments line on your Form 1040 or 1040-SR. For additional information, see Form 8689 for the year of the tax return you are amending.

Refund or Amount You Owe The purpose of this section is to figure the additional tax you owe or excess amount you have paid (overpayment). All of your payments (for the tax year you are amending) received up to the date of this amended return are taken into account, as well as any overpayment on your original return or after adjustment by

Instructions for Form 1040-X (Rev. December 2025) 9

the IRS. It is as if you were using the new information to complete your original return. If the results show a larger overpayment than before, the difference between the two becomes your new overpayment. You can choose to receive the refund or apply it to your estimated tax for the following year. In either case, it can be used by the IRS to pay other federal or state debts that still exist. If the results show that you owe, it is because you don’t have enough additional withholding or because filing your original return with the information you have now would have resulted in a smaller overpayment or a balance due.

Line 18—Overpayment

Enter the overpayment from your original return. If your original return was changed by the IRS and the result was an additional overpayment of tax, also include that amount on line 18. Don’t include interest you received on any refund. Any additional refund you are entitled to on Form 1040-X will be sent separately from any refund you haven’t yet received from your original return.

Line 19—Amount Available To Pay Additional Tax

If line 18 is larger than line 17, line 19 will be negative. You will owe additional tax. To figure the amount owed, treat the amount on line 19 as positive and add it to the amount on line 11. Enter the result on line 20.

Line 20—Amount You Owe

The IRS recommends paying the amount due on line 20 electronically whenever possible. If you file Form 1040-X electronically, you can simultaneously authorize the Treasury to make an electronic withdrawal (direct debit) for the balance due.

You can also make a secure payment:

• Online using Direct Pay, cash, or your IRS online account; or

• Online or by phone using the Electronic Federal Tax Payment System (EFTPS), a debit card, a credit card, or a digital wallet such as Click to Pay, PayPal, or Venmo.

Go to www.irs.gov/Payments/pay-by-check-or-money-order for details on paying by check or money order.

See the Amount you owe section in your income tax return instructions or go to IRS.gov/Payments for additional details on payment options.

Line 23—Overpayment Applied to Estimated Tax

Enter on line 23 the amount, if any, from line 21 you want applied to your estimated tax for next year. Also enter that tax year in the space provided. No interest will be paid on this amount.

If you owe past-due federal or state debts, all or part of your overpayment will be used to pay the past-due amounts. You will receive a notice if any of your overpayment has been applied to past-due amounts, so you will know how much was applied to your estimated tax.