Business Tax Deadlines

State filing information

Alaska

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

checked 2026-09-01Verified against Alaska Department of Revenue, Tax Division; some details could not be confirmed (see below). 8 sources.

Corporate income tax return

May 15
Per the Form 6000 instructions (rev. 01/01/2025): the Alaska return must be filed on the 15th day of the month following the federal due date; for C...

Partnership / S corporation returns

April 14
Partnerships April 14; S corporations April 15

Sales tax return

None
no state sales and use tax; local

Other business taxes

None noted
No franchise, gross receipts, or entity-level tax found.

Alaska Department of Revenue, Tax Division

Rules in full

Corporate income tax

Per the Form 6000 instructions (rev. 01/01/2025): the Alaska return must be filed on the 15th day of the month following the federal due date; for C corporations generally that is the 15th day of the 5th month after year end (June year-ends: October 15). Older guidance and many secondary sources phrase this as '30 days after the federal due date'.

Extension. A federal extension automatically extends the Alaska filing date to the 15th day of the month following the federal extended due date...

Partnerships and S corporations

No entity-level tax on S corporations; no PTE election (Alaska has no individual income tax). Note the 6000 instructions say the partnership return is due 'the 15th day of the month following the federal due date' while the 6900 instructions say 'within 30 days' and explicitly warn it is not necessarily the 15th; the two official instruction sets differ by a day.

Notes

Official Tax Division page states: 'The State of Alaska currently does not have a sales and use tax; however, some local jurisdictions impose local sales taxes.' No franchise, gross receipts or LLC annual tax is administered by the Tax Division; the biennial report is a Division of Corporations (DCCED) filing and was not chased.

What we could not confirm. The Form 6000/6900 instructions were read from a taxformfinder.org mirror of the official DOR PDFs (rev. 01/01/2025) because the official tax.alaska.gov forms index is script-rendered; no tax.alaska.gov HTML page stating the due-date rule was fetched. AS 43.20.030 statute text was not retrieved. Secondary sources still describe the C-corp rule as '30 days after federal', which yields the same May 15 date for calendar-year filers but can differ by a day for other year ends.

Federal dates that apply in Alaska

  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://tax.alaska.gov/ official
  2. https://tax.alaska.gov/programs/index.aspx official
  3. https://tax.alaska.gov/programs/programs/index.aspx?10002 official
  4. https://www.taxformfinder.org/forms/2024/2024-alaska-form-6000i.pdf
  5. https://www.expressextension.com/statetaxextension/alaska/business-tax-extension/
  6. https://www.instead.com/state-tax-deadlines/2025-alaska-state-tax-deadlines
  7. https://www.taxformfinder.org/forms/2024/2024-alaska-form-6900i.pdf
  8. https://www.salestaxinstitute.com/jurisdiction/alaska

Checked 2026-09-01; researcher confidence 0.70. Corrections with a link to the state's own page: contact@businesstaxdeadlines.com.