Louisiana Corporate Tax Rate: 5.5% Flat, Franchise Repeal, Deadlines

The Louisiana corporate tax rate is a flat 5.5% of Louisiana taxable income for tax years beginning on or after January 1, 2025, replacing the older graduated brackets.¹ The state’s separate corporate franchise tax has also been repealed for periods beginning on or after January 1, 2026, so no new franchise tax accrues from that point forward.² Both changes came out of the 2024 Third Extraordinary Legislative Session.

Who Pays the 5.5% Rate

The flat 5.5% applies to every C corporation doing business in Louisiana, calculated on Louisiana taxable income with no graduated brackets.¹ Act 5 of the 2024 session also created a $20,000 corporate standard deduction, so every corporation gets a baseline reduction before the rate is applied.³

Two situations get a different rate. S corporations filing composite returns for nonresident shareholders pay 3%, and pass-through entities that elect to be taxed at the entity level also pay 3%.⁴

What Happened to the Franchise Tax

Act 6 of the 2024 session eliminated the corporate franchise tax for tax periods beginning on or after January 1, 2026.² Before the repeal, corporations owed $2.75 for every $1,000 of capital employed in Louisiana above a $300,000 threshold.⁵

If your corporation carries any unpaid franchise tax from earlier periods, that liability is still owed. Only new franchise tax obligations disappear starting in 2026.

How Multistate Corporations Figure Louisiana Income

You owe Louisiana corporate income tax only if your business has enough connection to the state to create nexus. A physical footprint such as an office, warehouse, or in-state employees creates nexus outright. Significant sales into Louisiana can also trigger a filing obligation on economic-nexus grounds, without any physical presence.

For companies operating in more than one state, Louisiana uses single sales factor apportionment. Your Louisiana sales divided by your total sales everywhere gives the percentage of income the state can tax. Property and payroll no longer figure into the formula.

Federal Public Law 86-272 carves out a narrow protection: a state cannot tax the income of a company whose only in-state activity is soliciting orders for tangible personal property that are approved and filled from outside the state. That safe harbor does not reach companies selling services or digital goods, and it does not apply to Louisiana-incorporated entities. Sales activity that goes beyond solicitation, such as repairs, credit checks, or collections, can also break the protection.

Filing Deadlines and Extensions

Corporations file on Form CIT-620, using the same fiscal year as the federal return. The return is due the 15th day of the fifth month after the fiscal year closes. For calendar-year filers, that means May 15. If the deadline lands on a weekend or holiday, the next business day applies.⁴

Louisiana grants an automatic six-month extension if you timely requested a federal extension. No separate state extension form is required; you just check the box on the return. The extension covers filing only. Any tax you expect to owe must be paid by the original due date, or interest and penalties will run on the unpaid balance regardless of the extension.⁴

Electronic Filing

Any corporation with total assets of $250,000 or more (in absolute value) must file electronically.⁶ The Department of Revenue handles e-filing through its Louisiana File Online portal.

Estimated Payments

Corporations expecting to owe more than $1,000 for the year generally need to make quarterly estimated payments. Underpayment can trigger additional interest, so the quarterly schedule matters even if the annual return is filed on time.

Penalties for Late Filing or Payment

Filing late costs 5% of the total tax due for each 30-day period (or fraction of one) the return is delinquent, capped at 25%.⁷ Three months late already means a 15% penalty on top of the underlying tax.

Interest is a separate charge that runs from the original due date until the tax is paid in full. The rate is set at three percentage points above the Louisiana judicial interest rate and cannot exceed 1.25% per month.⁸ The rate fluctuates, so check the Department of Revenue’s posted rate before running your own calculation.

Willful conduct is a different matter. Anyone required to collect or pay over state taxes who willfully fails to do so faces a fine of up to $10,000, up to five years in prison, or both.⁹ The statute targets willfulness, not honest mistakes, though ignoring repeated notices can narrow that distinction.

Credits That Changed in 2024

The 2024 reform ended several longstanding incentive programs on June 30, 2025: the Quality Jobs Program, the Enterprise Zone program, the Angel Investor Tax Credit, and the Sound Recording Investor Tax Credit.³ The legislature signaled that replacement programs would be considered in the 2025 Regular Session, so check with the Department of Revenue and Louisiana Economic Development before assuming a specific credit is available.

The motion picture production credit survived but with tighter limits. Productions can claim a 25% base credit on qualified in-state expenditures, with additional increments for Louisiana-written screenplays, filming outside the New Orleans metro area, Louisiana resident payroll, and visual effects work, up to a combined 40%.¹⁰ Beginning July 1, 2025, the annual cap on credits issued fell from $150 million to $125 million, the cap on credits claimed also dropped to $125 million, and unused amounts no longer roll forward.³

Other notable adjustments: the C corporation inventory tax credit sunsets June 30, 2026, though unused credits keep their carryforward with a five-year extension; the historic rehabilitation credit cap dropped from $125 million to $85 million for applications received on or after January 1, 2025; and a new $12 million annual cap now applies to the research and development credit starting July 1, 2025.³

If You Disagree With an Assessment

When the Department of Revenue assesses additional tax, you have 60 calendar days from the date on the notice to either pay or appeal to the Louisiana Board of Tax Appeals.¹¹ Missing the window makes the assessment final.

An appeal should explain clearly why the assessment is wrong and attach supporting documents. The Board is an independent forum for tax disputes outside the regular court system, generally faster and less expensive than litigation. Either side can appeal the Board’s decision into Louisiana state court.

Interest keeps accruing on the disputed amount during an appeal. Some corporations pay under protest and then pursue a refund to stop the interest clock. That tradeoff is worth working through with a tax professional before choosing a path.

1
Louisiana State Legislature. Louisiana Revised Statutes Title 47 RS 47:287.12 – Rates of Tax
2
Louisiana Department of Revenue. Is the Corporation Franchise Tax Repealed?
3
Louisiana Department of Revenue. 2024 Third Extraordinary Session Legislative Summaries
4
Louisiana Department of Revenue. CIT-620i 2025 Corporation Income Tax Return Instructions
5
Louisiana Department of Revenue. Corporation Income and Franchise Taxes
6
Legal Information Institute. Louisiana Administrative Code Title 61 III-1505 – Corporation Income Tax Returns Electronic Filing Requirements
7
Justia Law. Louisiana Revised Statutes Title 47 RS 47-1602 – Specific Penalties
8
Louisiana State Legislature. Louisiana Revised Statutes Title 47 RS 47:1601 – Interest
9
Justia Law. Louisiana Revised Statutes Title 47 RS 47-1641 – Criminal Penalty for Failing to Account for State Tax Moneys
10
Louisiana State Legislature. Louisiana Revised Statutes Title 47 RS 47:6007 – Motion Picture Production Tax Credit
11
Louisiana State Legislature. Louisiana Revised Statutes Title 47 RS 47:1565 – Notice of Assessment and Right to Appeal