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​​​​​Filing requirements and guidance

Corporations that are doing business in Oregon, or with income from an Oregon source, are required to file an Oregon corporation tax return. 

If a corporation is doing business in Oregon, they generally must file an excise tax return for the privilege of doing business in Oregon. Excise tax is measured by net income. Excise tax fil­ers are subject to corporation minimum tax. 

If a corporation is not doing business in Oregon, but they have income from an Oregon source, they generally must file an income tax return. Income tax fil­ers are not subject to corporation minimum tax. 

Please note: Merely registering your corporation with the Oregon Secretary of States office does not create a filing obligation.

If you file a consolidated Oregon return and have more than one affiliate doing business in Oregon or with Oregon-source income, you must complete Schedule OR-AF and submit it with your return.

Select a topic to get more tax information:

Stay current

Read the current corporation excise and income tax topics, including recent Oregon legislation.

Tie to Federal Tax Law

In general, Oregon is tied to the federal definition of taxable income as of April 1, 2021; however, Oregon is still disconnected from:

• Federal subsidies for prescription drug plans (IRC §139A; ORS 317.401).
• Deferral of certain deductions for tax years beginning on or after January 1, 2009 and before January 1, 2011 may require subsequent Oregon modifications (IRC §168(k) and §179; ORS 317.301).​​

Due dates

Oregon corporation returns are due the 15th of the month following the due date of the corresponding federal return. For example, if a calendar year federal corporation return is due April 15, the Oregon calendar year return is due May 15. If a due date falls on a weekend or state holiday, the return is due the next business day. Corporation due dates aren't affected by Emancipation Day.


The Oregon extended due date is the 15th day of the month following the federal extended due date. Don’t send the extension form separate from your Oregon return. Include it with your return. See the corporation form instructions for complete information.

Corporation excise and income​ tax credits


Cost of performance rule change

The 2017 Oregon Legislature decided that, starting with the 2018 tax year, corporate excise taxpayers must use market-based sourcing principles rather than cost of performance for receipts other than those from the sale of tangible personal property. We amended OAR 150-314-0435 to reflect the new market-based sourcing standard. View the previous version of OAR 150-314-0435​ for tax years prior to 2018. 

If you cannot locate the prior version of a different administrative rule, contact the department's rules coordinator.

Contact us

Phone: 503-378-4988.

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