- Louisiana residents must file state tax returns by the Friday, May 15, 2026, deadline to avoid penalties.
- An automatic six-month extension delays the filing deadline until November 16, but all payments remain due in May.
- The 2025 tax year features a new 3% flat tax rate, replacing the previous multi-bracket system for all filers.
(LOUISIANA) — The Louisiana Department of Revenue said individual state income tax returns for tax year 2025 are due on Friday, May 15, 2026, with residents required to file Form IT-540, the Louisiana Resident Income Tax Return, or an equivalent return by that date.
Residents can file electronically at no cost through the LaTAP portal, use commercial tax software, or submit paper forms available from the department’s forms page. The Louisiana Department of Revenue calendar lists Friday, May 15, 2026 as the deadline for individual income tax returns and says credit card payments will be accepted that day.
Louisiana also provides an automatic 6-month filing extension through November 16, 2026, under Act 410 of the 2022 Louisiana Legislature. No request is required.
That extension covers filing, not payment. Tax owed remains due on May 15, 2026, and late payments trigger penalties and interest.
Byron Henderson, Louisiana Department of Revenue public information director, said in a May 12, 2025 update that sets out the same filing pattern used for 2026, “Tax payments submitted after the May 15. deadline are subject to penalties and interest.”
The state deadline stands apart from federal storm relief announced earlier this year. IRS Announcement LA-2026-01 moved certain federal tax deadlines to March 31, 2026 for Louisiana residents affected by severe winter ice storms that began on January 22, 2026.
That federal relief does not change Louisiana’s state filing date of May 15, 2026. As of May 11, 2026, the Louisiana Department of Revenue had not announced matching state relief.
The department began accepting 2025 returns on January 26, 2026. It says electronic refunds generally arrive within 4 weeks, while paper-filed refunds can take up to 8 weeks.
Those timelines give electronic filing another practical advantage as the deadline approaches. Residents using Form IT-540 through the LaTAP portal or commercial software typically move through the process faster than paper filers, especially during the final days before the deadline.
The filing season also arrives under Louisiana’s new individual income tax structure. The state shifted to a flat 3% individual income tax rate effective January 1, 2025, and that rate applies to 2025 returns filed in 2026.
That change replaced the prior brackets of 1.85%, 3.5%, and 4.25%. The new rate gives the 2025 filing year a different tax calculation than the one many residents used on earlier returns.
Estimated payment deadlines for the 2026 tax year also begin this month. The due dates are May 15, 2026, June 15, 2026, September 15, 2026, and January 15, 2027.
Louisiana listed separate business deadlines as well. C corporations must file by May 15, 2026 using Form CIFT-620, and they receive an extension to November 15, 2026.
S corporations and partnerships face a later date for the next tax cycle. Their deadline for the 2026 tax year is March 15, 2027.
The Louisiana Department of Revenue directs residents with questions to revenue.louisiana.gov or to Henderson at [email protected]. With May 15, 2026 now days away, the state’s message is narrow and direct: file the return by the deadline, and pay any tax due by the same day even if the automatic extension pushes the paperwork deadline to November 16, 2026.
