Arkansas is genuinely an April-15-for-all state — unlike the federal calendar, it does not use the March 15 pass-through deadline. It has also cut its income tax rates repeatedly, and it offers an elective pass-through entity tax.

Arkansas Tax Deadlines at a Glance (2026)

Arkansas puts every entity type on April 15, 2026 — the 15th day of the 4th month — including S corporations and partnerships. Arkansas adopted the April 15 date for pass-throughs for tax years beginning on or after January 1, 2016, so it does not follow the federal March 15 deadline. This is a genuine, distinctive Arkansas rule, and all returns extend to October 15.

Rates Have Been Cut Repeatedly

Arkansas’s top individual income tax rate is 3.9% for 2025 (reduced from 4.4%), applying to net taxable income above roughly $25,700. The top corporate rate is 4.3% for 2025 (down from 4.8%), on a graduated schedule of 1%, 2%, 3%, and 4.3%. Both have been cut through recent legislation and continue to trend downward.

The Elective Pass-Through Entity Tax

Arkansas’s elective Pass-Through Entity Tax (Form AR1100PET) lets S corporations and partnerships pay at the entity level — at 3.9% on ordinary income (1.95% on capital gains), tracking the top individual rate — with owners receiving a credit, a federal SALT-cap workaround. The PET return is also due April 15, and the election is made before the (extended) return due date.

Estimates, Extensions, and Penalties

Individual estimated payments (AR1000ES) are due April 15, June 15, September 15, 2026, and January 15, 2027. The interest rate on unpaid tax is 10% per year, and the failure-to-pay penalty is 5% per month. An extension covers filing only, not payment.

CPA Action Steps

• File every Arkansas return — including S-corps and partnerships — by April 15

• Apply the 3.9% top individual and 4.3% top corporate rates for 2025

• Consider the 3.9% PET election (1.95% on capital gains)

• Remember Arkansas does not use the federal March pass-through date

Verify current rates and dates against the Arkansas Department of Finance and Administration (dfa.arkansas.gov) before filing.