Louisiana state income tax — ITIN filer guide

Louisiana taxes income at a flat 3% (tax year 2026), administered by the Louisiana Department of Revenue. This guide covers who must file, how filing with an ITIN works, whether the state EITC applies to you, and when refunds arrive.

FLAT rate: 3%

  • State return form: IT-540
  • Deadline (tax year 2026): May 15, 2027 — Louisiana's statutory deadline is May 15 (falls on a Saturday in 2027, so expect Monday, May 17, 2027); automatic 6-month filing extension
  • Who must file: Louisiana residents who are required to file a federal individual income tax return must file a Louisiana return
  • State sales tax: 5%
  • Scheduled change: Flat 3% replaced the graduated 1.85%-4.25% structure for tax periods beginning on/after Jan 1, 2025; standard deduction inflation-indexed beginning 2026

Louisiana refund timing

  • E-filed returns: LDR: expected processing for electronically filed returns is up to 45 days
  • Paper returns: LDR: paper returns may take as long as 14 weeks
  • Check your Louisiana refund status

State tax agency

  • Louisiana Department of Revenue — revenue.louisiana.gov
  • Phone: 855-307-3893
  • Free filing option: Louisiana Taxpayer Access Point (LaTAP) — free electronic filing of Form IT-540 through the LDR portal

Facts verified 2026-06-11 against official state sources (primary source). Figures refresh with every dataset review.

Filing with an ITIN

Your ITIN is fully accepted on the Louisiana state return — states accept the IRS-issued taxpayer number, the same one you use federally. The flow is always the same:

  1. Complete your federal return first (Form 1040 + ITIN)
  2. Transfer your federal figures to IT-540
  3. Apply state-specific deductions and credits
  4. E-file — Louisiana Taxpayer Access Point (LaTAP) — free electronic filing of Form IT-540 through the LDR portal
  5. Or visit a VITA site for free in-person preparation

Louisiana state EITC — do ITIN filers qualify?

The federal EITC requires valid SSNs for you, your spouse, and qualifying children — ITIN filers can never claim it. What varies is the STATE credit:

Louisiana Earned Income Credit — 5% of the federal EITC (refundable)

✗ SSN required (not available to ITIN filers)

LA EIC requires qualifying for the federal EITC (La. R.S. 47:297.8); the federal SSN requirement excludes ITIN-only filers; Louisiana is not on NILC's ITIN-EITC list

See how all 52 jurisdictions compare on the state tax hub and which tax credits ITIN filers can claim.

Last verified: 2026-06-11. Primary source: Louisiana Department of Revenue.

General procedural information for educational purposes. Not legal or tax advice. State tax rates change frequently — verify current figures with the state agency before filing. For case-specific guidance, consult a tax professional, enrolled agent, or CPA.