Oregon CAT guide
How to file the Oregon Corporate Activity Tax
A practical walk-through of filing the Oregon CAT — what to gather, where to file, the deadlines, and the mistakes that trip people up.
Last reviewed June 2026 against Oregon Department of Revenue guidance.
What you'll need
- Your total Oregon commercial activity for the tax year
- Cost of goods sold and labor costs apportioned to Oregon (for the 35% subtraction)
- A Revenue Online account with the Oregon Department of Revenue
Step by step
- 1Register for the CAT through Revenue Online within 30 days of exceeding $750,000 in Oregon commercial activity.
- 2Calculate your taxable commercial activity: subtract 35% of the greater of COGS or labor costs (capped at 95% of activity).
- 3If you expect $5,000 or more of CAT for the year, make quarterly estimated payments (Apr 30, Jul 31, Oct 31, Jan 31).
- 4File Form OR-CAT through Revenue Online by April 15 and pay any remaining balance.
Where to file
Oregon Corporate Activity Tax Return
Form OR-CAT (150-106-003)
Official form / filing portalDeadlines
Annual, with quarterly estimated payments if CAT ≥ $5,000.
- Annual return (OR-CAT)April 15
- Q1 estimateApril 30
- Q2 estimateJuly 31
- Q3 estimateOctober 31
- Q4 estimateJanuary 31
Common mistakes to avoid
- Registration ($750k) and filing ($1M) are different thresholds — you can be required to register before you owe any tax.
- Missing a required quarterly estimate triggers a 5% underpayment penalty.
- The 35% cost subtraction cannot exceed 95% of your Oregon commercial activity.
Estimate your Oregon CAT and get a pre-filled worksheet first.
Open calculatorGeneral information, not tax advice — confirm the current procedure with the Oregon Department of Revenue or a qualified CPA before filing.