Alabama Tax Assessment and Refund Petition Deadlines

Alabama’s Department of Revenue generally has three years to audit a return and assess additional tax, and taxpayers generally have the later of three years from filing or two years from payment to claim a refund. Those are the two deadlines that govern most Alabama tax assessment and refund petition timing, and each has its own trigger, its own exceptions, and its own trap for the unwary.

When the Three-Year Assessment Clock Starts

Under Alabama Code § 40-2A-7(b)(2), the Department has three years to issue a “preliminary assessment” for any underpayment. The clock starts on the return’s due date or the date you actually filed, whichever is later.¹ If no return is required for a particular tax, the three years run from the date the tax was due.

The “whichever is later” rule matters for early filers. File your individual return on March 1 and the clock still doesn’t start until April 15. Filing early never shortens the state’s audit window. Alabama’s individual income tax return shares the same due date as the corresponding federal return.²

Once three years pass with no preliminary assessment, the Department generally loses the ability to pursue additional tax for that period.

When the Assessment Window Extends or Disappears

Three situations push the deadline beyond three years, and two eliminate it entirely.

Substantial omission: if a return understates the taxable base by more than 25 percent, the Department gets six years from the due date or filing date, whichever is later.¹
Fraudulent return filed with intent to evade tax: can be assessed at any time, with no deadline.¹
No return filed: the state can assess whenever it discovers the gap, because the clock never started.¹

Written Extensions by Agreement

Before the assessment period expires, the Department and the taxpayer can agree in writing to extend it. This often happens during an audit that won’t wrap up in time. The extension can be renewed by additional written agreements as long as each one is signed before the prior agreement expires.¹ Signing is voluntary. Refusing one, though, may prompt the state to issue a preliminary assessment on whatever information it has rather than lose the right to assess at all.

The Refund Petition Deadline

If you overpaid, the deadline to file a petition for refund is the later of two dates: three years from the date the return was filed, or two years from the date the tax was paid.³ If no return was timely filed, the window shrinks to two years from payment only.

The structure matters most when payment and filing happen at different times. Say you filed your 2024 return on April 15, 2025 and paid the balance the same day. Three years from filing reaches April 15, 2028; two years from payment reaches April 15, 2027. You get April 15, 2028, the later date. Now suppose you filed on time but didn’t make the final payment until June 1, 2026. Two years from that payment reaches June 1, 2028, which beats the three-year-from-filing date, so June 1, 2028 becomes your deadline.

How Much You Can Actually Recover

Filing a timely petition doesn’t guarantee you recover every dollar you overpaid. The lookback depends on which deadline you’re relying on. If you file within the three-year window from the return due date, you can recover the tax paid during that three-year period plus any amount paid during a filing extension. If you missed the three-year window and are relying on the two-year-from-payment rule, your refund is limited to the tax paid within the two years before the petition was filed.³ A timely petition can still produce a partial refund if some of the overpayment falls outside the applicable lookback.

Extension Agreements Preserve Refund Rights

If you signed a written agreement extending the assessment period, your refund deadline automatically extends to match. The petition may be filed at any time before the extended assessment period expires.¹ Extending the state’s audit power can preserve a refund right that would otherwise expire.

If a Preliminary Assessment Arrives, the 30-Day Clock Takes Over

Once the Department issues a preliminary assessment inside the three-year window, the three-year rule is no longer what protects you. A new, much shorter deadline does. You have 30 calendar days from the date of the assessment to file a written petition for review with the Department of Revenue.⁴ The petition can be the Department’s own form or a written statement with your name, address, phone number, the type of tax, the periods you’re contesting, and your reasons for disagreeing. Attach supporting documentation.

Miss the 30 days and the Department converts the preliminary assessment into a final assessment.⁴ The same conversion happens if the Department reviews your protest and decides the assessment should stand. From the final assessment, you have 30 days from the mailing or personal service date to appeal in writing to the Alabama Tax Tribunal in Montgomery.⁵ Missing the Tribunal’s 30-day window typically ends your administrative appeal rights.

How to File a Refund Petition

Alabama uses different refund forms depending on the tax type and how the tax was paid. For sales, use, rental, and lodgings taxes paid directly to the Department, the form is the Direct Petition for Refund (ST-5). If you paid those taxes to a seller rather than the state, you’d use Form ST-6.⁶ For business license and other tax types, the Department provides its own petition forms (B&L: RP for a single-party petition, or B&L: RJ when both parties must sign).⁷ Picking the wrong form can delay processing.

Every petition must identify the tax period, state the exact dollar amount claimed, and explain why the original payment exceeded what was legally owed. The Department requires documentation: invoices, receipts, amended return calculations, or whatever supports the claim.⁷ No refund will be issued without a properly filed petition, so gather your W-2s, 1099s, and corrected records before starting.

Petitions can be submitted through the My Alabama Taxes (MAT) online portal or mailed to the Department of Revenue in Montgomery. Electronic filing through MAT tends to process faster and gives you an immediate confirmation of receipt. If mailing on paper, use certified mail so you have proof of the filing date, because that date determines whether you met the deadline.

What Happens After You File

The Department has six months from the date your petition is filed to grant or deny the refund. If it doesn’t act within that window, the petition is automatically deemed denied, and that deemed denial triggers your right to appeal to the Alabama Tax Tribunal. The six months can expire silently without a formal notice, so mark the date and follow up if you haven’t heard back.

Collection Is a Separate Clock

A final assessment doesn’t start the three-year or six-year rules again, and it doesn’t give the Department forever to collect. Alabama tax liens remain enforceable for 10 years from the date the lien is filed, after which the lien becomes unenforceable by lapse of time.⁸ Bankruptcy and extended out-of-state residence can suspend that 10-year clock under Alabama Code § 40-29-52.⁹ If your concern is how long the state can chase a bill that has already been finally assessed, the collection rules — not the assessment rules — are the ones to work from.

1
Alabama Legislature. Alabama Code 40-2A-7 – Uniform Revenue Procedures
2
Alabama Department of Revenue. Due Dates
3
Cornell Law Institute. Alabama Admin Code Rule 810-14-1-.19 – Time Limitations for Filing Petitions for Refund
4
Alabama Department of Revenue. Preliminary Assessment Appeal Rights
5
Alabama Department of Revenue. When Do the Appeal Rights for a Final Assessment Expire
6
Alabama Department of Revenue. Direct Petition for Refund
7
Alabama Department of Revenue. Petition for Refund Filing Instructions
8
Alabama Department of Revenue. What Is the Duration of a Tax Lien
9
Alabama Legislature. Alabama Code 40-29-52 – Suspension of Running of Period of Limitations