Key figures
Oregon accounting
2026, with sources
Two corporate taxes
Oregon taxes a C corporation twice, on two different bases. The corporate excise tax, filed on Form OR-20, is an income tax: 6.6% on the first $1 million of Oregon taxable income and 7.6% above it, never less than a minimum tax that scales with Oregon sales ($150 below $500,000 of sales). The Corporate Activity Tax (CAT), filed on Form OR-CAT, is a gross receipts tax: 0.57% of taxable Oregon commercial activity above $1 million, plus $250, after subtracting 35% of the larger of cost inputs or labor costs.
For the books, the excise tax belongs in the income tax provision; the CAT, measured on receipts, is generally accounted for as an operating tax. A startup with $600,000 of Oregon revenue owes only the excise minimum ($500 at that sales level) in a loss year, and has to register for the CAT once Oregon commercial activity reaches $750,000.
Federal conformity after SB 1507
Oregon ties its definition of taxable income to federal law as it applies to the tax year, and its other references to the Internal Revenue Code to a fixed date, which SB 1507 (2026) moved to December 31, 2025. That rolling tie means federal changes to taxable income — including the 2025 return to expensing of domestic research costs — reach Oregon unless the legislature disconnects.
SB 1507 did disconnect in two places that matter to startups: federal bonus depreciation under §168(k) is added back for property placed in service in tax years beginning on or after January 1, 2026, and the §1202 exclusion for qualified small business stock no longer applies for Oregon from 2026. Each creates a state-only deferred tax item in the provision.
Apportionment and filing
Oregon apportions business income by a single sales factor and files unitary groups on a consolidated basis: the Oregon return starts from the federal consolidated return, removing non-unitary affiliates. Net losses carry forward 15 years with no carryback, and the carryforward is reduced by Oregon income in intervening years.
Deadlines
- 15th day of the month after the federal due date — May 15 for calendar yearsCorporation excise tax returnForm OR-20
- Annually, with quarterly estimatesCorporate Activity Tax return, if Oregon commercial activity exceeds $1 millionForm OR-CAT
- QuarterlyExcise tax estimates when the year’s tax, including the minimum, is $500 or moreEstimated tax
The federal baseline
This page covers what Oregon adds. The federal rules underneath it apply here too.
Common questions
Does Oregon have a corporate income tax or a gross receipts tax?
Both can apply. The excise tax is an income tax: 6.6% of Oregon taxable income up to $1 million, 7.6% above, with a minimum tax based on Oregon sales. The CAT is a separate gross receipts tax, 0.57% of taxable commercial activity over $1 million plus $250, owed whether or not the company is profitable.
Does Oregon follow the federal Section 174 rules?
Oregon’s definition of taxable income follows federal law as it applies to the tax year, so the federal treatment of research costs generally flows through. The exceptions Oregon has written are the ones to track: SB 1507 decouples from federal bonus depreciation and the Section 1202 exclusion from 2026.
When is the Oregon corporate return due?
A month later than the federal return. Form OR-20 is due on the 15th day of the month after the federal due date, so May 15 for a calendar-year corporation, and a federal extension carries over to Oregon.
Accounting next door
- CACalifornia accountingCalifornia taxes corporations at 8.84% with an $800 minimum franchise tax, apportions by a single sales factor with market sourcing, and does not follow federal Section 174 amortization or bonus depreciation.
- IDIdaho accountingIdaho taxes corporations at a flat 5.3% with a $20 minimum, apportions by a single sales factor, and conforms to the Internal Revenue Code as of January 1, 2026, except bonus depreciation.
- NVNevada accountingNevada has no corporate income tax. It taxes Nevada gross revenue above $4 million a year through the Commerce Tax, and payroll through the Modified Business Tax.
- WAWashington accountingWashington has no corporate income tax; it taxes gross receipts through the B&O tax, at 0.471% for retail sales (including SaaS) and 1.5%–2.1% for other services since October 2025.
Founder guides on this
- US GAAPUS GAAP for early-stage startups, in plain EnglishAccrual accounting, revenue recognition (ASC 606), leases (ASC 842), stock compensation and capitalized software: what each means for a small company.
- R&D taxThe R&D tax credit and Section 174A for startupsEngineering salaries can earn a federal R&D credit against payroll tax, and Section 174A lets you deduct US research again. What qualifies, what to track.
- FundraisingAudit-ready books before your Series AInvestors, lenders and auditors ask for the same things: accrual statements, reconciled accounts and support for every balance. How to be ready first.
More of the Oregon guide
- ReceivablesReceivables and sales tax in OregonSales tax registration, economic nexus, whether SaaS is taxable, and collecting from customers
- PayablesPayables and contractors in OregonPaying vendors and contractors: 1099 filing, use tax, contractor tests and withholding
- PayrollPayroll taxes and employer rules in OregonWithholding, unemployment insurance, paid leave, minimum wage and the rules on paydays
- ComplianceCompliance and filings in OregonRegistering to do business, annual reports, franchise tax and the filing calendar
- AdvisoryAdvisory: credits and decisions in OregonCredits, incentives and the decisions that are cheaper to get right the first time
Sources
Checked against each agency’s own page on . Rates and thresholds change, usually on January 1.
General information for US companies, not tax, legal or accounting advice for yours. Rules and thresholds change; confirm the specifics with a CPA or the agency before you act on them.