Washington business tax extension
Washington has no corporate income tax. Washington's business tax is the business and occupation (B&O) tax, a gross receipts tax reported on the Excise Tax Return in My DOR. The federal extension is Form 7004, due for calendar-year corporations and for partnerships and S corporations. In general, an extension gives you more time to file, not more time to pay.
Last updated · From Washington's own forms, instructions and laws, cited below
Does Washington have a corporate income tax?
No. Washington has no corporate income tax.Washington's business tax is the business and occupation (B&O) tax, a gross receipts tax reported on the Excise Tax Return in My DOR. Your federal return still needs its own federal extension.
Washington's rules for each return, as its own instructions and laws state them:
Business and occupation (B&O) tax
- Return
- Excise Tax Return (reports B&O tax), filed in My DOR
- Due date
- Set by the assigned filing frequency: monthly returns the 25th of the next month, quarterly returns the end of the month after the quarter, annual returns April 15 of the next year
- Extension
- There is no automatic extension, and a federal extension has no effect. The department may grant an extension if asked before the due date (in My DOR, by phone or by secure email) for causes such as a computer failure, lost records, a medical emergency or a natural disaster, but not for cash flow. Most extensions are shorter than 30 days.
- Payment
- An extension of more than 30 days requires paying the department an amount equal to the estimated tax for the period.
When a due date in Washington falls on a weekend or legal holiday, it moves to the next business day. Washington's holidays can differ from the federal ones, so a rule not tied to a federal date is given without a computed date.
When is the federal business extension due?
Corporations, S corporations, partnerships, multi-member LLCs, estates and trusts extend their federal return with Form 7004, filed by the return's original due date. The extension is automatic: no reason is needed and the IRS doesn't approve it. We e-file it for a flat $9.95. These are the 2027 dates for calendar-year 2026 returns:
| Return | Who files | File the extension by | Extended to |
|---|---|---|---|
| Form 1065 Partnerships & multi-member LLCs, Form 7004 | 6 months | ||
| Form 1120-S S corporations (and LLCs taxed as S corps), Form 7004 | 6 months | ||
| Form 1120 C corporations (and LLCs taxed as C corps), Form 7004 | 6 months | ||
| Form 1041 Estates & trusts, Form 7004 | 5½ months | ||
| Form 990, 990-EZ, 990-PF Tax-exempt organizations & private foundations, Form 8868 | May 15, 2027 is a Saturday | 6 months |
Federal dates follow the IRS rule: a deadline on a weekend or legal holiday moves to the next business day. A fiscal-year business counts from its own year-end; see the fiscal-year deadline guide.
Tax-exempt organizations extend the 990 series with Form 8868, not Form 7004. Each return needs its own extension, so extending a business return does not extend its owners' personal returns.
Does an extension give more time to pay?
No. A federal extension moves the filing deadline only: tax owed is due by the original due date, and the IRS charges interest and the late-payment penalty on anything paid after it. More in does an extension give you more time to pay?
Where are Washington's forms and instructions?
On the Washington Department of Revenue website, which has the current forms, instructions and online services. The rules on this page are summarized from the sources below. We e-file the federal extension; the Washington return and any Washington extension request go to the state.
Washington extension FAQ
Does Washington have a corporate income tax?
No. Washington's business tax is the business and occupation (B&O) tax, a gross receipts tax reported on the Excise Tax Return in My DOR. A federal return still needs a federal extension: Form 7004 for a business, filed by the return's original due date.
When is the Washington Excise Tax Return (reports B&O tax) due?
Set by the assigned filing frequency: monthly returns the 25th of the next month, quarterly returns the end of the month after the quarter, annual returns April 15 of the next year.
Does a Washington business still need a federal extension?
Yes, to get more time for its federal return: Form 7004, filed by April 15, 2027 for a calendar-year corporation or March 15, 2027 for a partnership or S corporation.
Sources
- Home | Washington Department of Revenue, read
- Business tax structure in Washington State, read
- Business & occupation tax, read
- Filing frequencies & due dates, read
- Annual business filers, read
- WAC 458-20-228, Returns, payments, penalties, extensions, interest, stays of collection, read
- Excise tax return extensions, read
Filing a federal business extension this season?
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