Alabama state taxes are due on different dates depending on which tax you owe: individual income tax returns are due April 15, sales tax is due by the 20th of the month after the reporting period, property tax becomes delinquent after December 31, and business returns fall on March 15, May 15, or another date tied to entity type. Miss any of them and the state adds penalties plus daily interest on the unpaid balance.
Individual Income Tax: April 15
Your Alabama individual income tax return for the prior calendar year is due April 15. If April 15 lands on a weekend or state holiday, the deadline moves to the next business day.1Alabama Department of Revenue. When Should I File My Alabama Individual Income Tax Return?
You only have to file if your adjusted gross income meets one of these thresholds:
- Single: $4,000
- Head of family: $7,700
- Married filing separately: $5,250
- Married filing jointly: $10,500
Nonresidents must file if their Alabama-source income exceeds their prorated personal exemption.2Alabama Department of Revenue. Individual Income Tax
If April 15 is going to be tight, Alabama automatically grants a six-month extension to October 15. You do not need to file any form to get it. The catch: the extension covers paperwork, not payment. Any tax you owe is still due on April 15, and interest and late-payment penalties start accruing the next day on any unpaid balance. Send an estimated payment by April 15 if you expect to owe.3Alabama Department of Revenue. Can I Apply for an Extension to File My Return?
Quarterly Estimated Tax Payments
If you have income that isn’t subject to withholding, such as self-employment earnings, rental income, or investment gains, you may need to send the Alabama Department of Revenue quarterly estimated payments. Calendar-year filers use four dates:
- Payment 1: April 15
- Payment 2: June 15
- Payment 3: September 15
- Payment 4: December 15
These dates stay the same every year unless they fall on a weekend or holiday.4Alabama Department of Revenue. When Are Estimated Tax Payments Due?
Alabama charges an underpayment penalty when the shortfall between what you owed and what you paid through withholding and estimated payments is at least $500. You avoid the penalty if your payments equal at least 90 percent of your current-year tax or 100 percent of last year’s tax. If your prior-year adjusted gross income was over $150,000 ($75,000 if married filing separately), the prior-year safe harbor rises to 110 percent.5Alabama Department of Revenue. Form 40ES Instructions
Sales and Use Tax: The 20th of the Month
Businesses that collect Alabama sales tax must file and remit by the 20th of the month following the reporting period. Monthly filers report each calendar month; quarterly filers report each quarter. If the 20th is a weekend or holiday, you get until the next business day.6Alabama Department of Revenue. Due Date Calendar for Taxes
Business Return Deadlines
Business filing dates depend on how your entity is structured.
S-Corporations and Partnerships
S-Corporations (Form 20S) and partnerships or LLCs (Form 65) file by March 15 for a calendar year. The earlier date gives owners time to receive their Schedule K-1 before the April 15 individual deadline.7Alabama Department of Revenue. Due Dates An S-corp or partnership that gets a federal extension gets a matching Alabama extension, but any tax owed is still due on the original date.8Alabama Department of Revenue. Corporate Income Due Date – Extensions
C-Corporations
Alabama gives C-Corporations one month beyond their federal due date, automatically. For calendar-year filers, the federal return is due April 15, so the Alabama return is due May 15. If the corporation takes a federal six-month extension to October 15, Alabama adds one more month, making the state return due November 15.8Alabama Department of Revenue. Corporate Income Due Date – Extensions
Business Privilege Tax
Every corporation, LLC, and limited partnership doing business in Alabama owes an annual business privilege tax on top of income tax. The privilege tax return is due on the same date as the entity’s corresponding federal income tax return.9Alabama Department of Revenue. Business Privilege Tax
New entities face a tighter deadline. The initial privilege tax return (Form BPT-IN) is due within two and a half months after the entity incorporates, organizes, qualifies, or begins doing business in Alabama. No extension is available for that initial return.10Alabama Department of Revenue. Alabama Business Privilege Tax
Property Tax: Due October 1, Delinquent After December 31
Alabama property taxes are paid in arrears, meaning you pay for the prior year of ownership. Taxes become due on October 1 and are delinquent after December 31. You pay through your local county revenue commissioner’s office, not the state Department of Revenue.11Alabama Department of Revenue. When Are My Property Taxes Due?
If you miss December 31, the timeline moves quickly. The taxes are classified as delinquent in January, the debt is turned over to the probate court in February, and the property is advertised for sale in April. A tax sale typically happens in May. The original owner then has a three-year redemption period to reclaim the property by repaying the purchaser’s costs plus additional fees.11Alabama Department of Revenue. When Are My Property Taxes Due?
Homestead exemption applications are handled at the county level, and the deadline generally falls on December 31. Contact your local revenue commissioner’s office to confirm the deadline and documentation.
Penalties and Interest for Missing a Deadline
Alabama penalizes filing late and paying late separately, and the two can stack.
Failure to File
If you don’t file by the deadline (including any extension), the penalty is the greater of 10 percent of any additional tax owed or $50.12Alabama Legislature. Alabama Code Title 40 Revenue and Taxation – 40-2A-11
Failure to Pay
The late-payment penalty depends on which return the tax sits on:
- Annual returns (income tax, business privilege tax): 1 percent of the unpaid tax for each month or partial month late, up to a maximum of 25 percent.
- Monthly or quarterly returns (sales tax, use tax, lodgings tax): a flat 10 percent of the tax not paid by the due date.
These penalties apply to the net tax liability remaining after credits and payments.13Cornell Law School. Alabama Admin Code 810-14-1-.30 – Penalty for Failure to Timely Pay Tax
Interest
Alabama also charges interest on unpaid tax from the day after the due date until the balance clears. The rate is set quarterly and is 7 percent for the first quarter of 2026. To estimate what you’ll owe, divide the annual rate by 365, then multiply by the number of days late and the amount owed.14Alabama Department of Revenue. Quarterly Interest Rates
How to File Your Return
Finish your federal return first, because the Alabama forms pull several figures from the federal calculations. Gather your W-2s, any 1099s for interest, dividends, or other income, and your completed federal return. Full-year residents use Form 40; part-year and nonresidents use Form 40NR.1Alabama Department of Revenue. When Should I File My Alabama Individual Income Tax Return?
Every individual taxpayer can file electronically for free through My Alabama Taxes (MAT), the state’s secure online portal, or through IRS-approved commercial software that supports Alabama e-filing. If you mail a paper return, the Department of Revenue uses different mailing addresses depending on whether your return includes a payment or claims a refund. Check the forms and mailing addresses page on the ALDOR website for the right one.15Alabama Department of Revenue. Individual Income Tax Electronic Filing Options