Filing the Arizona Form 140X to Amend a Tax Return

Taxpayers who discover an error on a previously filed Arizona individual income tax return have a method for correction. The state provides Form 140X, titled “Individual Amended Income Tax Return,” for this purpose. This form allows individuals to report changes to their income, tax liability, credits, or filing status after their original return has been accepted.

Common Reasons for Amending an Arizona Return

A primary trigger for amending is a change made at the federal level that impacts your Arizona tax liability. If the Internal Revenue Service (IRS) audits your federal return and makes adjustments to your federal adjusted gross income, you are required to report these changes to Arizona. You must file Form 140X within 90 days of the final determination by the IRS to avoid potential penalties.

Another frequent reason for amending a return is the receipt of corrected information documents after you have already filed. For instance, an employer might issue a Form W-2c (Corrected Wage and Tax Statement) with different wage or withholding amounts, or a financial institution could send a corrected Form 1099 for interest or dividend income. These corrected documents mean the income reported on your original return is inaccurate.

Taxpayers may also discover their own errors after filing. This could involve realizing you omitted a source of income, found receipts for deductions you failed to claim, or incorrectly calculated a credit. Similarly, you might determine that you used the wrong filing status. For example, if you filed as Single but later realize you qualified for Head of Household status, amending your return could result in a lower tax liability and a potential refund.

Preparing Your Amended Return with Form 140X

To begin the amendment process, you must gather a complete copy of the original Arizona tax return you are amending (Form 140, 140A, or 140EZ) and all supporting documents that substantiate the changes. Examples include the corrected Form W-2c or 1099, the official IRS audit report detailing federal adjustments, or records proving your eligibility for a deduction or credit you previously missed.

The official, current-year Form 140X is available for download on the Arizona Department of Revenue’s website. You must use the form specific to the tax year you are amending. While tax preparation software can often generate the form, it cannot be filed electronically. The state requires that all amended returns be printed and submitted by mail.

Completing Form 140X involves a three-column format. Column A, “As Originally Reported,” requires you to transfer the figures directly from your original Arizona return. Column C, “Corrected Amount,” is where you will enter the final, correct figures for each line item. The calculation occurs in Column B, “Net Increase or (Decrease),” where you will enter the difference between Column C and Column A for each corresponding line.

The form requires a detailed explanation of the changes. You must provide a reason for every adjustment reported on the form. For example, you might state, “Received a corrected W-2 from my employer which changed my state wages and withholding,” or “Amending to claim the XYZ tax credit, for which I am now eligible.” The Department of Revenue needs this information to understand the basis for the amendment, and failure to provide a sufficient explanation can lead to delays or rejection of the amended return.

Filing Procedures and Next Steps

Once you have accurately completed Form 140X and the explanation of changes, you must assemble the final submission packet. Attach all necessary supporting documents directly behind the Form 140X. If your state amendment was triggered by changes to your federal return, you must include a copy of the federal amended return, Form 1040-X, and any correspondence from the IRS, such as the audit report.

The completed packet must be mailed to the Arizona Department of Revenue, but the specific address depends on whether the amended return results in a refund or a tax payment. For returns resulting in a refund or no change in tax, the mailing address is P.O. Box 52138, Phoenix, AZ 85072-2138. If your amended return shows you owe additional tax, you must mail it to a different address: P.O. Box 52016, Phoenix, AZ 85072-2016.

If you owe additional tax, you must include payment with your mailed return. You can pay by check or money order made payable to the Arizona Department of Revenue. Be sure to write your Social Security Number and the tax year you are amending on the payment to ensure it is applied to the correct account. The department also offers online payment options through its official website.

After mailing your amended return, you should anticipate a processing time of approximately 8 to 10 weeks. The department’s “Where’s My Refund?” tool cannot provide a status for your return until it has been in the system for at least six weeks. Once processing is complete, you will receive a notice in the mail, which will be a refund check, a confirmation of acceptance, or a bill for additional tax.