Louisiana S Corporation Tax Return: CIFT-620 and PTE Election

If your company has a federal S election, Louisiana S corporation tax return requirements will surprise you: the state does not recognize S corporation status for income tax purposes. Your business files Form CIFT-620 and pays Louisiana corporate income tax as if it were a C corporation, at a flat 5.5% rate for tax years beginning on or after January 1, 2025. A pass-through entity election can cut that to 3%, the franchise tax is gone starting in 2026, and calendar-year returns are due May 15.

Louisiana Taxes Your S Corporation Like a C Corporation

The Louisiana Department of Revenue puts it directly: “Louisiana income tax law does not recognize Subchapter S corporation status. An S corporation is required to file income tax in the same manner as a C corporation.”¹ Your federal 1120-S filing does not carry over. Louisiana taxes the entity itself on its Louisiana-source income, and shareholders separately report their share of the company’s income on their personal Louisiana returns.

The rate for tax years beginning on or after January 1, 2025 is a flat 5.5%, replacing the earlier graduated brackets.²

Form CIFT-620 and the Filing Deadline

The return is Form CIFT-620, the Louisiana Corporation Income Tax return. Calendar-year filers must file by May 15 of the following year. Fiscal-year filers have until the 15th day of the fifth month after their tax year ends. If that date falls on a weekend or holiday, the deadline moves to the next business day.¹

Louisiana grants an automatic six-month extension if you timely requested a federal extension. No separate state extension form is needed. The extension only pushes the filing deadline, not the payment deadline. Any expected balance must still be paid by the original due date, or interest starts running.¹

Quarterly Estimated Tax Payments

If your S corporation expects to owe $1,000 or more in Louisiana income tax for the year, it must make quarterly estimated payments.³ Payments are due on the 15th day of the 4th, 6th, 9th, and 12th months of the tax year. For a calendar-year corporation, that means April 15, June 15, September 15, and December 15.⁴ Underpayment triggers interest on the shortfall, so project your liability early. This matters even more if you make the PTET election, because the entity itself is carrying the tax obligation the shareholders would otherwise carry.

Cutting the Rate With a Pass-Through Entity Election

Louisiana lets S corporations elect pass-through entity tax (PTET) treatment under R.S. 47:287.732.2. When you make the election, the entity-level rate drops from 5.5% to the 3% individual income tax rate.⁵ Shareholders receive a corresponding credit against their individual Louisiana income tax, so the same income isn’t taxed twice.

The election also has a federal angle. Because the tax is paid by the entity, it comes off as a federal deduction at the entity level, sidestepping the $10,000 SALT cap that applies to individuals. For shareholders in higher brackets, that can produce real federal savings.

The election must be in writing. You can file it any time during the preceding tax year, or during the current tax year up to the 15th day of the fourth month after the tax year closes. Once made, it stays in effect for future years until terminated. Termination requires written consent from shareholders holding more than half the ownership interest and must be filed with the Department of Revenue by November 1 for calendar-year filers.⁶

The Franchise Tax Is Gone Starting in 2026

Louisiana’s corporate franchise tax has been repealed for all tax periods beginning on or after January 1, 2026.⁷ The tax previously applied to every corporation doing business in Louisiana, most recently at $2.75 per $1,000 of capital above $300,000.⁸ Watch the transition. A calendar-year corporation filing its 2025 return in 2026 still owes franchise tax for the 2025 period. From 2026 forward, the franchise tax line on Form CIFT-620 is zero.

Composite Returns for Nonresident Shareholders

If any nonresident individual shareholder has not signed a separate agreement with the Department of Revenue to file their own Louisiana return, your S corporation must file a composite return covering those shareholders. Corporations, resident estates and trusts, and partnership shareholders cannot be included on the composite return and must file their own Louisiana returns.

Penalties and Interest for Missing Deadlines

Filing CIFT-620 late brings a penalty of 5% of the tax due for the first 30 days, plus another 5% for each additional 30-day period the return stays delinquent, capped at 25%.⁹ The penalty runs on total tax due, so a large balance gets expensive fast.

Interest on unpaid tax runs from the original due date until payment, at a rate set three points above the judicial interest rate and reset annually. For 2026, the rate is 10.50% per year.¹⁰ Interest applies whether or not a penalty also applies, so a late return with unpaid tax attracts both.

Annual Report With the Secretary of State

Separate from the tax return, every Louisiana corporation must file an annual report with the Secretary of State and pay a $30 filing fee.¹¹ The report is due on the anniversary of the corporation’s formation and lists current officers, directors, and registered agent. Filing is available online through the Secretary of State’s site.

Missing this report can get the corporation marked inactive or administratively dissolved. That status can undercut your ability to enforce contracts, file lawsuits, or transact business in Louisiana. Reinstatement usually means filing the overdue reports, paying all outstanding fees, and sometimes additional penalties. Keep your registered agent information current as well, because a lapsed agent address means missed legal notices, including lawsuit filings that can lead to default judgments.¹²

1
Louisiana Department of Revenue. CIFT-620i Louisiana 2025 Corporation Income Tax Instructions
2
Louisiana Department of Revenue. What Is the Corporation Income Tax Rate?
3
Justia Law. Louisiana Revised Statutes Title 47 RS 47:287.654 – Installment Payments of Estimated Income Tax by Corporations
4
Louisiana Department of Revenue. CIFT-620ESi Declaration of Estimated Tax for Corporations General Information
5
Louisiana Department of Revenue. What Are the Income Tax Rates for S Corps and Other Pass-Through Entities Making the PTE Election?
6
Louisiana State Legislature. Louisiana Revised Statutes Title 47 – RS 47:287.732.2
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Louisiana Department of Revenue. Is the Corporation Franchise Tax Repealed?
8
Louisiana Department of Revenue. Corporation Income and Franchise Taxes
9
Justia Law. Louisiana Revised Statutes Title 47 RS 47:1602 – Penalty for Failure to Make Timely Return
10
Louisiana Department of Revenue. R-1111 Interest Rate Schedule
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Louisiana Secretary of State. Get Forms and Fee Schedule
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Louisiana Secretary of State. File Business Documents