How to Do an Addendum on My Taxes

An addendum to your taxes might involve changes on a previously filed return, or an addition of forms or information for your return. If you discover that you need to make changes that alter your tax or refund due, you’ll need to file an amended return. However, if you feel like you should provide extra information to explain a section of your return, you must wait until the Internal Revenue Service requests the information.

Make Changes to Your Return

Download Form 1040X and the 1040X instructions from the IRS website. Use this form to make changes to your original return.

Fill out your name, Social Security number and filing status in the top section of the form. If you’re using form 1040X to change your filing status, mark the box that shows your amended status. If you’re not changing your filing status, mark the box that matches the status claimed on your original return.

Gather a copy of your original return. Enter figures from your return in Column A of the 1040X form.

Calculate changes to your tax return that you’re reporting on Form 1040X. List the changes in Column C of your 1040X. There are four categories on the form: Income and Deductions, Tax Liability, Payments and Refund or Amount You Owe.

Report the difference between Column A and Column C amounts in Column B of the 1040X.

Explain the reason for your amendments on Page 2, Part III of the 1040X.

Assemble your amended return. It’s only necessary to include the 1040X form and a new copy of any forms or schedules directly affected by your changes. You don’t need to include your original return.

Look at the 1040X instructions and find the mailing address for the state you live in. Send your amendment by certified mail to the address listed. It may take the IRS eight to 12 weeks to process your return. If you’re receiving a refund as a result of your changes, the IRS will mail a paper check to the address on your form after processing is complete.

Send Additional Information

Wait for a letter from the IRS requesting more information.

Gather documents and tax forms for your response. If the IRS requests more information about something you claimed on your return, you may have to provide records such as receipts or statements that prove items you claimed.

Tear off the reply voucher at the bottom of your IRS notice. Attach your documents to the voucher and mail them to the address printed on the voucher. If you use the reply envelope provided by the IRS, insert the voucher so the address appears in the envelope window.