Business Tax Deadlines

State filing information

South Dakota

Business tax filing in South Dakota: state returns, sales tax, other business taxes, and the federal dates that apply everywhere.

checked 2026-09-01Verified against South Dakota Department of Revenue. 12 sources.

Corporate income tax return

None
South Dakota imposes no corporate income tax and no general franchise tax on corporations

Partnership / S corporation returns

Not confirmed
No state income tax return is required of partnerships or S corporations

Sales tax return

20th of the following month
sales and use tax · The Department assigns a filing frequency (monthly, quarterly, semi-annual, annual, or seasonal) when the license is issued, based on sales/tax...

Other business taxes

2 taxes
Contractor's Excise Tax (2% of gross receipts on construction services / realty improvement); Bank Franchise Tax (SDCL ch. 10-43)

South Dakota Department of Revenue

Other business taxes

TaxWho owes itDue
Contractor's Excise Tax (2% of gross receipts on construction services / realty improvement)Any person entering into a contract for construction services or engaged in construction, building, installation, or repair of a fixture to real property in South...Returns due the 20th of the month following the reporting period; electronic payments due the 25th; paper...
Bank Franchise Tax (SDCL ch. 10-43)Every financial institution (bank, savings and loan association, production credit association, etc.) regularly engaged in business in South Dakota during the yearWithin 15 days after the institution's federal income tax return is due (calendar-year C-corp bank: April 30)

Rules in full

Corporate income tax

South Dakota imposes no corporate income tax and no general franchise tax on corporations. The only income-based business tax is the Bank Franchise Tax on financial institutions (see other_business_taxes).

Partnerships and S corporations

None. No entity-level income tax and no PTE election exists.

Sales and use tax

Due date. Returns are due the 20th of the month following the reporting period. Electronic payments are due the 25th of that month; paper returns and paper payments are both due the 20th. Weekend/holiday due dates roll to the next business day.

Filing frequency. The Department assigns a filing frequency (monthly, quarterly, semi-annual, annual, or seasonal) when the license is issued, based on sales/tax volume; licensees are notified of their frequency.

Prepayments. None published; no accelerated or prepayment schedule for large filers found on official pages.

Notes

South Dakota is one of two states (with Wyoming) that levies neither a corporate income tax nor a gross receipts tax. State sales tax rate is 4.2% as shown on the July 2026 DOR guide. The 'April 30' bank franchise calendar date is derived from the '15 days after the federal return is due' rule and the federal April 15 date, not stated verbatim on the DOR page.

What we could not confirm. (1) Sales tax filing-frequency dollar thresholds are not published on dor.sd.gov or in the July 2026 Sales & Use Tax Guide; the DOR only says it assigns frequency at licensing. (2) Bank franchise tax rate not shown on the DOR page and sdlegislature.gov statute pages are JavaScript-rendered and could not be read, so no secondary source beyond the DOR laws-and-regulations page. (3) TaxJar states electronic payment is due 'the 30th day of the month following the due date', which conflicts with the DOR's 25th-of-the-month rule; the official DOR guide (20th return / 25th e-payment) is treated as authoritative. (4) Annual report is a Secretary of State filing and was not researched.

Federal dates that apply in South Dakota

  1. SEP15Tue
    Individuals & Sole Proprietors
    Q3 2026 estimated tax payment (Form 1040-ES)
  2. SEP15Tue
    Partnerships
    Form 1065 extended return (Form 7004), tax year 2025
  3. SEP15Tue
    S-Corporations
    Form 1120-S extended return (Form 7004), tax year 2025
  4. SEP15Tue
    C-Corporations
    Q3 2026 corporate estimated tax (Form 1120-W)
  5. OCT15Thu
    Individuals & Sole Proprietors
    Form 1040 extended return (Form 4868), tax year 2025
  6. OCT15Thu
    C-Corporations
    Form 1120 extended return (Form 7004), tax year 2025

All 2026 federal deadlines

Sources

  1. https://dor.sd.gov/businesses/taxes/ official
  2. https://dor.sd.gov/ official
  3. https://dor.sd.gov/businesses/taxes/sales-use-tax/filing-and-paying-taxes-online-help/ official
  4. https://dor.sd.gov/media/avyep2sr/2026-7_sales-use-tax-guide.pdf official
  5. https://dor.sd.gov/businesses/taxes/sales-use-tax/ official
  6. https://dor.sd.gov/businesses/taxes/contractors-excise-tax/ official
  7. https://dor.sd.gov/media/1vgljwbp/2026-7-contractors-excise-tax-guide.pdf official
  8. https://dor.sd.gov/businesses/taxes/bank-franchise-tax/ official
  9. https://dor.sd.gov/businesses/taxes/bank-franchise-tax/bank-franchise-tax-laws-regulations/ official
  10. https://taxfoundation.org/data/all/state/state-corporate-income-tax-rates-brackets/
  11. https://www.avalara.com/taxrates/en/state-rates/south-dakota/south-dakota-sales-tax-guide.html
  12. https://www.numeral.com/blog/south-dakota-sales-tax-guide

Checked 2026-09-01; researcher confidence 0.85. Corrections with a link to the state's own page: contact@businesstaxdeadlines.com.