Home Business in King County, WA (2026)

6 county-level rules, plus city-specific rules for 7 cities in King County, Washington.

Verified from official government sources

Note: These county rules apply to unincorporated areas of King County. If you live within an incorporated city, that city's own rules apply — see the city list below.

Zoning Restrictions

Unincorporated King County allows home occupations as accessory uses in residential zones under KCC 21A.30.080. The business must be run by residents and stay clearly incidental to the residential use.

King County Home Business Zoning Rules

Some Restrictions

Full ordinance details →Official source ↗

Signage Rules

Unincorporated King County permits one non-illuminated sign for a home occupation, limited to 2 square feet and attached to the dwelling. Freestanding or illuminated signs are prohibited under KCC 21A.20.

King County Home Business Signage Rules

Some Restrictions

Full ordinance details →Official source ↗

Customer Traffic Restrictions

Unincorporated King County home occupations cannot generate traffic, parking, or deliveries beyond what is normal for a residential use, under KCC 21A.30.080. Routine commercial truck deliveries are prohibited.

King County Home Business Customer Traffic Limits

Some Restrictions

Full ordinance details →Official source ↗

Cottage Food Operations

Washington Cottage Food Act (RCW 69.22) lets residents make non-hazardous foods at home and sell up to $25,000 per year with a WSDA permit. King County also requires compliance with KCC 21A.30.080 home occupation rules.

King County Cottage Food and Home Kitchen Rules

Some Restrictions

Full ordinance details →Official source ↗

Home Daycare

Home-based child care in unincorporated King County requires a Washington State DCYF license (Family Home Child Care up to 12 children). KCC 21A.30.080 allows licensed daycare as a home occupation in residential zones.

King County Home Daycare Licensing Rules

Heavy Restrictions

Full ordinance details →Official source ↗

Home Occupation Permits

Unincorporated King County does not require a separate home occupation permit for businesses meeting KCC 21A.30.080 accessory use standards. A Washington State business license and B&O tax registration are required.