Idaho Taxes Pages

How to File an Amended Idaho Return

amend Idaho taxes
"The Gem State"

If you need to change or amend an accepted Idaho State Income Tax Return for the current or previous Tax Year, you need to complete Form 40 (residents) or Form 43 (nonresidents and part-year residents). You can prepare a current tax year Idaho Tax Amendment on, however you cannot submit it electronically. In comparison, the IRS requires a different Form - Form 1040X - to amend an IRS return (do not use Form 1040 for an IRS Amendment). 

The IRS might send you a notification to change an error on your Return, or you might have discovered an error. If you or the IRS amended or changed one of your IRS Tax Return(s), the IRS will report this to the Idaho Tax Agency, thus you should file an Idaho Amendment within one year.

Prepare only a ID State Return without an IRS return. Details
Step by Step instructions on how to only Prepare and Download - not eFile - State Returns on
File an Idaho Tax Amendment
You can prepare it here on However, you cannot submit it electronically.
Option 1: Sign into your account, modify your Return and download/print the ID Form 40 (residents) or Form 43 (nonresidents and part-year residents) under My Account. Check the "Amended Return" box, sign the form, and mail it to one of the addresses listed below.
Option 2: If you don't have an account follow the step by step instruction on how to prepare a tax return/amendment.
Option 3: If you want to do the math on your own paper return then complete, sign ID Form 40 or Form 43 - Print, Mail the Form to ID State Tax Commission to:
Idaho State Tax Commission
P.O. Box 56
Boise, ID 83756-0056
ID Tax Amendment Form 40 or 43
This Form can be used to file a: Tax Return, Tax Amendment, Change of Address. Check the "Amended Return" box on the Form.
Step 1: Download, Complete Form 40 (residents) or 43 (nonresidents and part-year residents) for the appropriate Tax Year below.
Step 2: Sign, Mail Form 40 or 43 to one of the addresses listed above
Current Tax Year only: Prepare online on until the October Deadline. When done Print, Sign and Mail in - Your Tax Amendment, Address Change, etc.
After Oct. Deadline Prepare, Print, Sign and Mail-In - see address above, ID Form 40 or Form 43
How to correct a rejected Tax Return
If your ID Tax Return was rejected by the ID Tax Agency - not - instructions on how to correct a rejected Idaho Tax Return.
Check Your ID Tax Amendment Status
1. Call the ID State Tax Commission at (800) 972-7660
2. Contact the ID State Tax Commission
Idaho Refund Deadlines
A. Three years from the due date of the original tax year return, including valid filing extensions.
B. One year from the final determination of the amended federal return or federal change, whichever is later, provided that the allowable refund is not more than the decrease in Idaho tax attributable to the federal change or correction.
C. Two years from the payment of an assessment, provided the amended return raises issues relating only to the prior assessment and the refund does not exceed the amount of tax paid on the prior assessment.
D. Two years from the filing of an amended Idah return resulting in the payment of additional tax, provided that the current amended return raises issues relating solely to the prior amended return and that the refund does not exceed the amount of the tax payment made as a result of the prior amended return.
Additional Idaho Tax Income Taxes Deadlines
Idaho Income Tax Penalties
Find out how Idaho Late Filing and Late Payment Penalties are calculated.
For IRS Tax and Late Filing Penalties we have an easy to use tool: The PENALTYucator.
File an IRS Tax Amendment by Tax Year
Instructions on how to prepare an IRS Tax Amendment on, however the IRS does not accept Tax Amendments electronically.

Will I get a bigger tax refund in 2024?

Many taxpayers can expect a bigger tax refund on their 2023 taxes. To help you keep up with soaring inflation, the IRS is making bigger changes than usual that could save you big money on your 2023 taxes, which is the tax return you'll file in 2024.

Take control of your personal life relationships, finances, and taxes: follow the tips on this page and keep up with tax planning for next year. You can use this free 2023 Tax Refund Calculator to get a high-level understanding of your taxes.