Key figures
Washington compliance
2026, with sources
Registering a Delaware corporation
A Delaware corporation registers with the Secretary of State by filing a Foreign Registration Statement ($180), then files an annual report ($70) by the end of each anniversary month. Separately, it applies for a business license through DOR’s Business Licensing Service, which issues the UBI number and opens the excise tax account. ESD and L&I accounts follow when the first employee is hired.
Excise returns, not income returns
The combined excise tax return is the main recurring filing: B&O by classification, retail sales tax collected by location code, and use tax on untaxed purchases, on a monthly, quarterly or annual schedule that DOR assigns based on volume. A company with no activity in a period still files.
Cities with their own B&O tax, such as Seattle, Bellevue and Tacoma, require their own license and returns, usually on thresholds well below the state’s. Seattle also levies a payroll expense tax, but only on businesses whose prior-year Seattle payroll exceeds $9,074,409 (2026 threshold).
Unclaimed property
Washington’s unclaimed property program sits inside DOR. Holders report and pay once a year, before November 1; because November 1, 2026 is a Sunday, DOR’s reminder for this year is November 2. For a startup the usual items are uncashed payroll and vendor checks and customer credit balances.
Deadlines
- By the end of the registration anniversary monthSecretary of State annual report for a registered foreign corporationAnnual report
- Monthly by the 25th; quarterly by the end of the month after the quarterB&O and sales tax, on the frequency DOR assignsCombined Excise Tax Return
- Before Nov 1 (Nov 2 in 2026)Report and remit unclaimed property to DORUnclaimed property holder report
The federal baseline
This page covers what Washington adds. The federal rules underneath it apply here too.
Common questions
How do we get a Washington business license?
Through the Department of Revenue’s Business Licensing Service, which issues the Unified Business Identifier (UBI) used by DOR, ESD and L&I, and adds city endorsements for cities that license through the state. The Secretary of State registration as a foreign corporation is a separate $180 filing.
What replaces the state corporate return in Washington?
There is none for income. Washington’s recurring filings are the excise tax return (B&O and sales tax), the quarterly ESD and L&I reports, the annual Secretary of State report and the unclaimed property report. City B&O returns are separate where the city has its own tax.
Compliance next door
- IDIdaho complianceA Delaware corporation registers in Idaho for $100, files an annual report each anniversary month on SOSBiz, and files Form 41 by April 15 with at least $20 of minimum tax.
- OROregon complianceA Delaware corporation pays $275 to register in Oregon and $275 a year to renew, files Form OR-20 by May 15, and in Portland files a combined city and county business tax return.
Founder guides on this
- ComplianceFirst-year compliance calendar for a Delaware C-corpDelaware franchise tax, 1099s, the federal return, payroll filings, state annual reports and sales tax: the deadlines a young C-corp misses most, by month.
- Sales taxSales tax nexus for startups: when you owe tax in a stateSince Wayfair, selling into a state can create a sales tax obligation. How economic nexus works, why SaaS is taxable in some states and when to register.
More of the Washington guide
- AccountingAccounting and state tax in WashingtonCorporate tax, conformity to federal rules, apportionment and what it does to your books
- ReceivablesReceivables and sales tax in WashingtonSales tax registration, economic nexus, whether SaaS is taxable, and collecting from customers
- PayablesPayables and contractors in WashingtonPaying vendors and contractors: 1099 filing, use tax, contractor tests and withholding
- PayrollPayroll taxes and employer rules in WashingtonWithholding, unemployment insurance, paid leave, minimum wage and the rules on paydays
- AdvisoryAdvisory: credits and decisions in WashingtonCredits, 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.