The five that catch people out
- 1 FebW-2s and 1099-NECs to the people who earned them, and to the agencies. 31 January 2027 is a Sunday.
- 15 MarS-corporation and partnership returns, with their K-1s.
- 15 AprIndividual returns, Q1 estimates, the Arts Tax, Metro SHS and Preschool for All.
- 15 SepExtended S-corporation and partnership returns, and the K-1s that go with them.
- 15 OctExtended individual returns. Filing only — the payment was due in April.
Dates for the 2027 filing season (tax year 2026). The month-by-month calendar below is the complete list, including the payroll and Washington-side dates.
January and early February 2027
- 15 January — Q4 2026 estimated tax payment, federal and Oregon
- 1 February — W-2s to employees and the Social Security Administration (31 January 2027 is a Sunday)
- 1 February — Form 1099-NEC to recipients and the IRS
- 1 February — Q4 federal payroll return, Form 941
- 31 January — Q4 Oregon combined payroll report
- 1 February — Form 940 FUTA annual return
- New rates and thresholds take effect across most Oregon and local taxes
March 2027
- 15 March — S-corporation returns (Form 1120-S) and K-1s to shareholders
- 15 March — Partnership returns (Form 1065) and K-1s to partners
- 15 March — Extension deadline for both, which extends filing but not payment
April 2027
- 15 April — 2026 individual returns, federal and Oregon
- 15 April — C-corporation returns (Form 1120)
- 15 April — Q1 estimated payments, federal and Oregon
- 15 April — Portland Arts Tax
- 15 April — Metro SHS and Multnomah Preschool for All personal returns
- 15 April — Portland Business License Tax and Multnomah County Business Income Tax, for calendar-year filers
- 15 April — Prior-year IRA contributions
- 30 April — Q1 payroll returns
June to August 2027
- 15 June — Q2 estimated payments
- 2 August — Q2 federal payroll return, Form 941 (31 July 2027 is a Saturday)
September to November 2027
- 15 September — Q3 estimated payments
- 15 September — Extended S-corporation and partnership returns
- 15 October — Extended individual returns
- 1 November — Q3 federal payroll return, Form 941 (31 October 2027 is a Sunday)
Ongoing and Washington-side
- Oregon CAT — quarterly estimated payments where liability exceeds the threshold; annual return in April
- Washington B&O — monthly, quarterly or annual filing depending on your assigned frequency
- Washington capital gains tax — generally due with the federal return date
- Washington Paid Family and Medical Leave — quarterly reporting for employers
- Oregon combined payroll — quarterly, covering withholding, unemployment insurance, Paid Leave, transit taxes
Questions this guide does not answer
Guides are general. Your return is not. An appointment costs less than a wrong assumption.
Written by
Bookkeeper, 25+ years
Katie has kept books for small businesses for more than 25 years — QuickBooks, payroll, AP, AR, reconciliations and monthly reporting.
Reviewed by
Heather Perkins
Enrolled Agent, Oregon Licensed Tax Consultant
Last reviewed
This page is general information about Oregon, Washington and federal tax rules, not advice about your own return. Thresholds and rates change every year. Figures were verified as of August 2026 — check the linked official sources, or talk to us about your situation.