Tax Calendar
Louisiana Business Tax Deadlines 2026
⚠️ Note: Tax deadlines that fall on a weekend or federal holiday shift to the next business day. Always verify current deadlines with your accountant. This calendar reflects the standard 2026 schedule.
January
February
March
April
May
June
July
August
September
October
November
December
Key Louisiana-Specific Notes
- ✓ Parish sales tax returns: due the 20th of the following month (state + each parish separately)
- ✓ Louisiana corporation income tax (CIFT-620): due May 15 for calendar-year corps
- ✓ Louisiana individual income tax (IT-540): due May 15 for calendar-year filers
- ✓ Louisiana extends filing deadlines when the IRS grants federal extensions
- ✓ Different parishes may have different filing systems — some use LaTAP, others use separate portals
Related Resources
Louisiana Tax Deadlines — Frequently Asked Questions
When is Louisiana parish sales tax due each month?
Louisiana parish sales tax returns and payments are due by the 20th of the month following the reporting period. For example, sales tax collected in January is due by February 20th. If the 20th falls on a weekend or holiday, the deadline moves to the next business day. Quarterly filers follow the same pattern but file every three months.
When are Louisiana business tax returns due?
Louisiana state income tax returns follow the same deadlines as federal returns for most entity types. Louisiana corporation income tax (Form CIFT-620) is due May 15 for calendar-year corporations (one month after the federal April 15 deadline). Louisiana individual income tax (Form IT-540) is due May 15 for calendar-year filers. Extensions are available.
When are S-Corp and partnership federal tax returns due?
S-Corporation (Form 1120-S) and partnership (Form 1065) federal returns are due March 15 for calendar-year entities. A 6-month extension to September 15 is available. Note that extensions give more time to file — not more time to pay. If the entity has tax owed, payment is still due by March 15.
What happens if I miss a Louisiana sales tax deadline?
Louisiana sales tax penalties for late filing are 5% per month on the unpaid tax, up to 25% maximum. Interest accrues on unpaid amounts at the applicable rate plus 3% per year. The minimum penalty for filings more than 60 days late is $100. Penalties and interest compound quickly — the sooner you file and pay, the less the total liability. ASU helps clients bring delinquent accounts current.
What are quarterly estimated tax deadlines for 2026?
Federal quarterly estimated tax payments for 2026 are due: April 15 (Q1), June 15 (Q2), September 15 (Q3), and January 15, 2027 (Q4). Louisiana follows the same schedule for state estimated payments. Estimated taxes apply to anyone who expects to owe $1,000 or more in federal taxes for the year. Business owners, self-employed individuals, and investors typically need to make quarterly payments.