South Dakota tax deadlines (2026 tax year)
For returns filed in 2027. Different year? See South Dakota 2025 deadlines →
No state individual income tax return required. South Dakota levies no individual income tax.
Federal deadlines that still apply (2026 tax year)
| Individual (Form 1040) | April 15, 2027 · extension October 15, 2027 |
|---|---|
| S-corp (1120-S) & partnership (1065) | March 15, 2027 |
| C-corp (Form 1120) | April 15, 2027 |
| Estimated payments | April 15, 2026 · June 15, 2026 · September 15, 2026 · January 15, 2027 |
Frequently asked questions
Does South Dakota have a state income tax?
South Dakota does not levy a broad individual income tax, so there is no state individual return to file for the 2026 tax year. You still need to file your federal return, and any state business, franchise, or excise taxes that apply to you.
What deadlines still apply if I live in South Dakota?
Your federal deadlines still apply: individual returns are due April 15, 2027, with an extension to October 15, 2027, and federal estimated payments are due April 15, 2026, June 15, 2026, September 15, 2026, January 15, 2027.
Dates are the standard statutory deadlines for the 2026 tax year and move to the next business day when they fall on a weekend or holiday. Always confirm the current dates with the South Dakota Department of Revenue or the IRS. This is general information, not tax advice.