Key takeaways
- An S corporation doing business in Arkansas files Form AR1100S with a copy of the federal return, unless it elects the pass-through entity tax and files Form AR1100PET instead.
- Arkansas is April 15 for calendar-year entities, a month after the federal Form 1120-S date, and payment is due on the original date even with an extension.
- Nonresident shareholders trigger withholding or a composite return, and the AR1099PT is due to them March 15, a month before the entity return.
- DFA's last published withholding and PET rate is 3.9% (tax year 2024). Act 1 of 2026 sets a 3.7% individual rate for 2026, but DFA has not yet applied it to the PET or withholding.
What Arkansas requires from an S corporation
Arkansas treats a federal S election as an Arkansas election. Under ACA 26-51-409(b), an election made on Form 2553 for federal purposes is deemed made for Arkansas, and for tax years beginning on or after January 1, 2018 a federal S corporation also has to file as an Arkansas S corporation. There is no separate Arkansas election form to chase for current-year clients.
The entity files Form AR1100S with a copy of the federal Form 1120-S attached, plus the Arkansas Schedule K-1 (AR K-1) for each shareholder. The AR K-1 is not a copy of the federal Schedule K-1 (Form 1120-S). The instructions say federal amounts may need adjusting for capital gains, interest, depreciation, Section 179 and contributions, and each shareholder's figure is the Arkansas total multiplied by ownership percentage. If the federal return shows Section 179 or depreciation, ask for the Arkansas depreciation schedule before you build the AR K-1.
The corporation also has to be registered with the Arkansas Secretary of State. The franchise tax report belongs to that office, not to AR1100S, and runs on its own deadline. Check the client's Secretary of State account separately before telling them they are current.
Due dates and extensions for 2026 returns
The federal Form 1120-S for tax year 2026 is due on the 15th day of the third month, which is March 15, 2027 for calendar-year clients. Arkansas Form AR1100S is due the 15th day of the fourth month, April 15, 2027.
Two routes give more time. A federal Form 7004 carries the Arkansas return to the federal extended due date. Form AR1155 is the Arkansas request: 180 days from the original Arkansas due date, or 60 days beyond the automatic federal extension due date. Act 629 of 2021 adds one month past the extended federal due date, only where a federal extension was requested, so do not promise it to a client relying on AR1155 alone.
An extension extends filing, not payment. Tax is due April 15, interest runs at 10% per annum from then, and the failure-to-pay penalty is 5% per month. The Arkansas failure-to-file penalty is also 5% per month, each capped at 35%, with a separate $50 penalty for failing to file at all.
The federal Form 1120-S late-filing penalty is separate: $255 per shareholder per month, up to 12 months, for returns due in 2026 (tax year 2025). Check the 2026 instructions for the amount on returns due in 2027.
The pass-through entity tax election
Act 362 of 2021 created an elective entity-level income tax for tax years beginning on or after January 1, 2022, for members holding 50% or more. The election is made by registering for the tax in ATAP or by completing Form AR362, by the extended due date of the return. The registration form is AR362-E and the revocation form is AR362-R.
An electing S corporation files Form AR1100PET and does not file Form AR1100S. The tax is due April 15 for calendar-year filers. C corporations, trusts and sole proprietorships cannot elect. DFA says the PET is subject to the Arkansas Tax Procedures Act and links a penalty and interest waiver for it.
DFA sets the PET rate at the highest individual rate, with capital gains taxed at one half. For tax years beginning in 2024 that was 3.9% on income and 1.95% on capital gains. Act 1 of the 2026 First Extraordinary Session (HB1001), approved 5/6/26, sets the individual rate at 3.7% above the lower brackets for tax years beginning on or after January 1, 2026. I found no DFA publication applying that to the 2026 PET, so treat a 2026 PET quote as an estimate.
Nonresident shareholders: withholding or composite
If the S corporation has a nonresident shareholder with Arkansas-source income, it must withhold at the highest applicable rate unless an exception applies. DFA's withholding page gives 3.9% for 2024. For a 2026 shareholder, use 3.9% as the last published rate and recompute once DFA confirms the 2026 figure. Take the Arkansas-source share, multiply by the rate, and remit it. For example, a nonresident with 40% of $200,000 of Arkansas-source income has an $80,000 share and $3,120 of withholding at 3.9%.
Withholding is not required if the shareholder's share is less than $1,000, the shareholder signs an agreement to file and pay, or the shareholder elects composite filing. The shareholder opts out by signing AR4PT. Keep the signed AR4PT in the file, because it is your support for not withholding if DFA asks.
The entity registers for a withholding pass-through account on Form AR1R or in ATAP. It furnishes AR1099PT to each nonresident shareholder by March 15, then files Form AR941PT with payment by April 15. Penalties and interest start April 16. The instructions also say failure to report and remit may let the Director revoke the S election, so treat a missed AR941PT as more than a late fee.
If you miss the AR1099PT or AR941PT dates, file and pay promptly, then ask DFA about relief; its withholding page points to a FAQ.
Composite returns and shareholders who move
A composite return, AR1000CR, lets the entity pay for nonresident shareholders who agree to be included, on AR4PT-A. The 2025 instructions tax non-corporation members at 3.9% and corporate members at 4.3%, with no deductions or credits.
Only nonresident members who must file Arkansas nonresident returns can be included. If a shareholder moved into or out of Arkansas during the year, ask when. A member who was a resident for part of the year is a poor fit for the composite and should file their own AR1000 or AR1000NR with the AR1099PT attached, so do not rely on the December 31 address alone. An entity cannot be a composite member.
More than nine members requires submitting member data on a USB flash drive. The extension is Form AR1055-CR, mailed by April 15 with any tax owed. Whoever signs the composite return signs for the group, so brief that person on the liability before they sign.
What to collect from the client
Get the final federal Form 1120-S with every Schedule K-1 (Form 1120-S) and the shareholder ledger. You need each shareholder's state of residence on December 31, 2026, a street address, the ownership percentage and the date of any move or ownership change during the year.
Ask for the Arkansas apportionment support: where goods ship from and to, where services are performed, and payroll by state. Arkansas is phasing out the throwback rule under Act 485 of 2023, with throwback sales sourced 57.13% to Arkansas for tax years beginning in 2026, according to the 2024 instructions.
Ask for any signed AR4PT or composite election already on file, prior AR941PT filings, the withholding account number and the Secretary of State franchise tax confirmation. Use this wording: "Please send the 2026 K-1s, each shareholder's state of residence on December 31, and any signed AR4PT forms by February 15, so we can meet the March 15 AR1099PT date." February 15 is our own buffer, not a rule.
Until DFA publishes the 2026 AR1100S and AR1100PET forms and rate tables, work from the 2025 forms as a placeholder, and say so in the engagement notes. A request list in Usual with a secure upload link and automatic reminders can hold the AR4PT forms and residency answers per client.