Business Tax Deadlines

State filing information

Oregon

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

checked 2026-09-01Verified against Oregon Department of Revenue. 15 sources.

Corporate income tax return

May 15
Oregon has two corporate taxes: the corporation EXCISE tax...

Partnership / S corporation returns

March 15
Partnerships March 15; S corporations April 15

Sales tax return

None
No statewide sales tax.

Other business taxes

3 taxes
Corporate Activity Tax (CAT); Corporate minimum tax (part of the corporation excise tax)

Oregon Department of Revenue

Other business taxes

TaxWho owes itDue
Corporate Activity Tax (CAT)Any business or unitary group with Oregon commercial activity of $750,000 must register (within 30 days of crossing); those with more than $1 million of Oregon...Annual return (Form OR-CAT) due the 15th day of the 4th month following the end of the tax year...
Corporate minimum tax (part of the corporation excise tax)C corporations doing business in Oregon pay the greater of calculated tax or the minimum tax ($150 to $100,000 based on Oregon sales)With the OR-20 / OR-20-S / OR-65 return (see corporate and pass-through due dates)
Pass-Through Entity Elective Tax (PTE-E)ElectiveApril 15 (return and payment); extended due date October 15

Rules in full

Corporate income tax

Oregon has two corporate taxes: the corporation EXCISE tax (ORS ch. 317, for the privilege of doing business in Oregon, measured by net income, subject to minimum tax) and the corporation INCOME tax (ORS ch. 318, for corporations not doing business in Oregon but with Oregon-source income; no minimum tax). Returns are due the 15th day of the month following the due date of the federal corporation return (i.e., one month after the federal due date). Rate: 6.6% of Oregon taxable income up to $1 million, 7.6% on the excess over $1 million. C-corporation minimum tax is a table by Oregon sales of the filing group: under $500,000 = $150; $500,000-$999,999 = $500; $1M-$1,999,999 = $1,000; $2M-$2,999,999 = $1,500; $3M-$4,999,999 = $2,000; $5M-$6,999,999 = $4,000; $7M-$9,999,999 = $7,500; $10M-$24,999,999 = $15,000; $25M-$49,999,999 = $30,000; $50M-$74,999,999 = $50,000; $75M-$99,999,999 = $75,000; $100M and above = $100,000. Estimated payments required if expected tax is $500 or more, due April 15, June 15, September 15, December 15 for calendar-year filers.

Extension. Oregon honors a valid federal extension (Form 7004); mark the Extension checkbox on the Oregon return

Partnerships and S corporations

Entity-level minimums: a partnership doing business in Oregon owes the $150 minimum tax (Form OR-65); an S corporation doing business in Oregon owes the $150 minimum excise tax (Form OR-20-S). Elective Pass-Through Entity Elective Tax (PTE-E): entities taxed as S corporations or partnerships may elect annually; 9% on the first $250,000 of distributive proceeds, 9.9% above; Form OR-21 return and payment due April 15 (extended due date October 15; late returns not accepted); estimates due April 15, June 15, September 15 and January 15 (for 2026 only, Q1 and Q2 are both due June 15). SB 1510 extends PTE-E through tax years beginning before January 1, 2028.

Notes

Oregon has no general sales/use tax (only a vehicle use tax on new vehicles bought out of state). Changes 2024+: CAT 7-month extension without good cause for tax years beginning on/after 2024-01-01; PTE-E extended through tax years beginning before 2028-01-01; 2026 PTE-E Q1+Q2 estimates both due June 15. Annual report is a Secretary of State filing, not a DOR filing (not researched).

What we could not confirm. Secondary sources disagree on the calendar-year C-corp date: taxextension.com says April 15 while DOR (corp-requirements page and 2025 OR-20 instructions) says the 15th of the month after the federal due date, i.e., May 15; the official rule was used. The DOR tax-calendar page as summarized by the fetch tool showed 'April 15, 2026' for corporation returns and 'January 15, 2026' for the CAT Q4 estimate, which conflict with the program pages (May 15 / January 31); program pages and form instructions were treated as controlling. OR-20-INC (income-tax filers) due date assumed to follow the same OR-20 rule; not separately confirmed. Web search budget was exhausted before a Wolters Kluwer/Avalara-class secondary could be fetched for the corporate due date; Portland.gov (city agency) and discern.com serve as corroboration.

Federal dates that apply in Oregon

  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://www.oregon.gov/dor/Pages/index.aspx official
  2. https://www.oregon.gov/dor/programs/businesses/Pages/corp-requirements.aspx official
  3. https://www.oregon.gov/DOR/forms/FormsPubs/form-or-20-instructions_102-020-1_2025.pdf official
  4. https://www.oregon.gov/dor/programs/businesses/Pages/corp-estimated.aspx official
  5. https://www.portland.gov/revenue/policy-tax-return-due-dates official
  6. https://www.oregon.gov/dor/programs/businesses/Pages/partnership.aspx official
  7. https://www.oregon.gov/dor/forms/FormsPubs/form-OR-20-S-instructions_102-025-1_2024.pdf official
  8. https://www.oregon.gov/dor/programs/businesses/Pages/pass-through-entity-elective-tax.aspx official
  9. https://www.oregon.gov/dor/pages/tax-calendar.aspx official
  10. https://www.oregon.gov/dor/programs/businesses/Pages/sales-tax.aspx official
  11. https://www.oregon.gov/dor/programs/businesses/Pages/corporate-activity-tax.aspx official
  12. https://oregon.public.law/statutes/ors_317.090
  13. https://www.discern.com/resources/oregon-franchise-tax
  14. https://www.taxextension.com/states/business/oregon/
  15. https://www.wipfli.com/insights/articles/tax-salt-understanding-the-oregon-corporate-activity-tax

Checked 2026-09-01; researcher confidence 0.88. Corrections with a link to the state's own page: contact@businesstaxdeadlines.com.