Alabama estimated tax payments are due quarterly on April 15, June 15, September 15, and January 15 of the following year. You owe them if you expect your Alabama income tax to exceed withholding and refundable credits by $500 or more for the year. Payments go to the Alabama Department of Revenue (ADOR) through the My Alabama Taxes portal or by mailing Form 40ES with a check.
The state builds its system on the federal estimated tax framework but swaps in its own thresholds, so meeting your IRS obligations does not automatically cover you with Alabama.
Who Has to Pay
Two conditions have to be true. You expect to owe at least $500 in Alabama income tax for the year after subtracting withholding and refundable credits, and you expect those credits and withholding to fall short of your “required annual payment.”1Alabama Legislature. Alabama Code 40-18-80 – Payment of Estimated Tax by Individuals
The required annual payment is the smaller of:
- 90% of the tax on your current-year Alabama return, or
- 100% of the tax shown on your prior-year return (which must have covered a full 12 months).2Alabama Department of Revenue. Instructions for Form 2210AL Underpayment of Estimated Tax Penalty for Individuals
If your Alabama adjusted gross income exceeded $150,000 on last year’s return ($75,000 if married filing separately), the prior-year safe harbor rises from 100% to 110% of last year’s tax.2Alabama Department of Revenue. Instructions for Form 2210AL Underpayment of Estimated Tax Penalty for Individuals The 90% current-year option is still available at any income level, but you have to predict your earnings accurately for it to work.
The rules apply to Alabama residents and to nonresidents earning income sourced within the state. The typical people who get caught by them are the self-employed, landlords, investors realizing gains, and anyone with substantial interest or dividend income that no employer is withholding tax on.
Quarterly Due Dates for 2026
Alabama uses four installment dates for calendar-year taxpayers:
- First quarter: April 15, 2026
- Second quarter: June 15, 2026
- Third quarter: September 15, 2026
- Fourth quarter: January 15, 2027
None of the 2026 dates fall on a weekend or state holiday, so no adjustments apply this year. When a deadline does land on a weekend or holiday, it moves to the next business day. The schedule matches the federal one, so you can send your IRS and ADOR payments on the same day.
Fiscal-year taxpayers substitute the corresponding months of their own cycle. Farmers and fishermen who earn at least two-thirds of their gross income from those activities can skip the quarterly schedule entirely and make a single payment by January 15 of the following year.
How to Calculate What You Owe Each Quarter
ADOR provides Form 40ES with a worksheet. You project your Alabama taxable income for the year, apply deductions and credits, and divide the resulting tax by four. Each installment is 25% of your required annual payment.
The simplest safe-harbor approach is the prior-year method: take your total Alabama tax from last year’s return, divide by four, and pay that amount each quarter. The number is set before the year begins, and as long as you pay on time you are penalty-proof regardless of what you eventually owe. For high-income filers subject to the 110% rule, multiply last year’s tax by 1.10 before dividing.
The Annualized Income Method
If your income arrives unevenly, the annualized income installment method lets each quarter’s payment reflect income actually earned during that period rather than a flat 25% split. A real estate agent who closes most deals in the summer would owe less for the first quarter and more for the third. The method requires Schedule AI as part of Form 2210AL, where you calculate income, deductions, and tax for four cumulative periods and annualize the figures.2Alabama Department of Revenue. Instructions for Form 2210AL Underpayment of Estimated Tax Penalty for Individuals More paperwork, but smaller early-quarter payments when income is genuinely back-loaded.
Alabama Income Tax Rates
Alabama uses a graduated structure topping out at 5%:3Alabama Department of Revenue. Individual Income Tax
- Single filers: 2% on the first $500 of taxable income, 4% on the next $2,500, and 5% above $3,000
- Married filing jointly: 2% on the first $1,000, 4% on the next $5,000, and 5% above $6,000
Anyone earning enough to trigger estimated payments will land almost entirely in the 5% bracket, so a rough quarterly estimate is 5% of projected net taxable income divided by four.
How to Submit Your Payments
The My Alabama Taxes (MAT) portal is the primary online channel and supports ACH debit from a bank account as well as credit and debit card payments.4Alabama Department of Revenue. Make A Payment You can pay through MAT without creating a full account by using the guest payment link.
Card payments carry a convenience fee charged by the third-party processor, generally around 2% or more of the payment amount. On a $2,000 quarterly payment that adds roughly $40, which is worth weighing against a direct bank transfer.
Paper checks and money orders are still accepted when mailed with the Form 40ES voucher, and the mailing address appears on the voucher instructions. Electronic payment sidesteps any question about postmark date and gives you an instant confirmation number to keep with your records.
How Alabama’s Rules Differ From Federal Rules
The state and federal systems share the same deadlines and the same 90%/100%/110% safe-harbor structure, but they diverge in one place that matters:
- Trigger threshold: Alabama’s is $500, and the federal threshold is $1,000. You can owe the IRS nothing extra while still owing Alabama a penalty simply because the state bar is lower.5Internal Revenue Service. Form 1040-ES Estimated Tax for Individuals
- Safe harbor percentages: Both use 90% of the current year or 100% of the prior year, stepping up to 110% when AGI exceeds $150,000 ($75,000 married filing separately).2Alabama Department of Revenue. Instructions for Form 2210AL Underpayment of Estimated Tax Penalty for Individuals
- Quarterly deadlines: Identical.
- Penalty interest rate: Alabama ties its underpayment rate to the federal rate set under 26 U.S.C. § 6621. As of January 2025 the rate was 7%.6Alabama Department of Revenue. MEMO Revised Interest Chart – Effective January 1, 2025
If you are a freelancer or side-income earner with modest state liability, run the Alabama numbers separately. Meeting the federal safe harbor does not automatically cover the state.
Underpayment Penalties
If your combined withholding and estimated payments fall short of the required annual payment and you owe more than $500 when you file, ADOR assesses a penalty calculated on Form 2210AL.2Alabama Department of Revenue. Instructions for Form 2210AL Underpayment of Estimated Tax Penalty for Individuals The penalty is effectively interest on the shortfall for each quarter, running from the installment due date until the earlier of the payment date or the annual filing deadline.
The rate tracks the federal underpayment rate under 26 U.S.C. § 6621, which ADOR republishes in periodic memos. At 7% annually, a $2,000 shortfall left unpaid for six months costs about $70.6Alabama Department of Revenue. MEMO Revised Interest Chart – Effective January 1, 2025 Not catastrophic on its own, but it compounds if you fall behind early and never catch up.
The penalty applies quarter by quarter. A taxpayer who underpays only the first installment but pays the remaining three in full still owes a penalty on that first-quarter shortfall. The annualized income method on Schedule AI can help here: if your income legitimately arrived later in the year, you can show that the early-quarter payments were proportional to what you had actually earned.
Penalty Waivers and Disaster Relief
ADOR will waive all or part of the underpayment penalty in two situations:2Alabama Department of Revenue. Instructions for Form 2210AL Underpayment of Estimated Tax Penalty for Individuals
- You retired after reaching age 62 or became disabled during the current or prior tax year, and the underpayment resulted from reasonable cause rather than willful neglect. Attach documentation showing your retirement date and age, or the date of disability.
- The underpayment arose from a casualty, disaster, or other unusual circumstance that makes imposing the penalty inequitable. Attach supporting records such as police or insurance reports.
To request either waiver, check Box A in Part I of Form 2210AL, calculate the penalty normally in Part IV, then write the waived amount in parentheses next to line 13 and subtract it from the total. Attach a written explanation. ADOR reviews the request and decides whether to grant it, so the documentation needs to be thorough.
When a federal disaster declaration covers Alabama counties, ADOR typically follows the IRS in extending filing and payment deadlines for affected taxpayers, and estimated installments falling within the postponed period move to the new deadline without penalty. Watch ADOR announcements if severe weather hits your area; relief is often automatic for taxpayers whose address is in the designated zone.