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17 permits · verified 2026-09-25

What permits do you need to open a contractor or trade in King County?

In short

A contractor or trade in King County, WA has 2 permits that apply to every business of this type, plus 15 more that depend on your premises, signage or how you are set up. King County Department of Local Services, Permitting Division charges $50 a year for the heating, air-conditioning, ventilation systems and equipment installers license. 4 of the 17 are charged as a range or formula rather than a flat fee. Verified 2026-09-25 against the issuing agencies’ published fee schedules.

Permits particular to a contractor or trade in King County

Permits required, with issuing agency, fee, renewal term and the date each record was last verified against its source
Home Occupation — Allowed Under Zoning Standards (King County)only if it applies to youKing County Department of Local Services, Permitting DivisionNo feenot applicable2026-09-25
Contractor Registration — State Labor & Industries Applies (King County)only if it applies to youKing County Department of Local Services, Permitting DivisionNo feenot applicable2026-09-25
Heating, Air-Conditioning, Ventilation Systems and Equipment Installers Licenseonly if it applies to youKing County Department of Local Services, Permitting Division$50 a yearannual — licenses expire June 302026-09-25
Tank Removal Contractor Annual Certificationonly if it applies to youKing County Department of Local Services, Permitting Division$183 a year (2026; the minimum inspection-fee amount in KCC §27.10.320.A.1)annual2026-09-25
Contractor RegistrationWashington State Department of Labor and Industries$150.20 every two years2 years2026-09-03
Electrical Contractor Licenseonly if it applies to youWashington State Department of Labor and Industries$353.90 every two years; $306.20 if the renewal is completed online24 months2026-09-03
Plumbing Contractor Licenseonly if it applies to youWashington State Department of Labor and Industries$148.10 every two years2 years2026-09-03

Fees shown as a range or formula are set that way by the issuing agency — we do not average them into a single number.

Local permits that apply to every type of business in King County

Permits required, with issuing agency, fee, renewal term and the date each record was last verified against its source
General Business License — King County position (state license applies)only if it applies to youKing County Department of Local Services, Permitting DivisionNo feenot applicable — the County's Start and grow your business page states that King County does not have a business license requirement2026-09-25
Commercial Tenant Improvement / Alteration / Change of Use Permit (unincorporated King County)only if it applies to youKing County Department of Local Services, Permitting DivisionVaries — formula on the King County pageper project2026-09-25
Zoning Certification Letteronly if it applies to youKing County Department of Local Services, Permitting DivisionVaries — formula on the King County pageone-time2026-09-25
Commercial Building Permit — New Construction (unincorporated King County)only if it applies to youKing County Department of Local Services, Permitting DivisionVaries — formula on the King County pageper project; permit expiration per KCC §16.02.2902026-09-25
Plumbing / Gas Piping / Backflow Permitonly if it applies to youPublic Health – Seattle & King County, Environmental Health Services (pet business, water recreation, on-site sewage, and plumbing & gas piping programs)Varies — formula on the King County pageper project; renewal $682026-09-25

Fees shown as a range or formula are set that way by the issuing agency — we do not average them into a single number.

WA registrations that apply to every type of business

Permits required, with issuing agency, fee, renewal term and the date each record was last verified against its source
Articles of Incorporationonly if it applies to youWashington Secretary of State, Corporations and Charities Division$180 one-time filing on paper; $200 onlineno expiry, but a $70 annual report is due each year2026-09-03
Reseller Permitonly if it applies to youWashington State Department of Revenue, Business Licensing ServiceNo fee4 years, or 2 in defined circumstances2026-09-03
Certificate of Formation (LLC)only if it applies to youWashington Secretary of State, Corporations and Charities Division$180 one-time filing on paper; $200 onlineno expiry, but a $70 annual report is due each year2026-09-03
Annual Reportonly if it applies to youWashington Secretary of State, Corporations and Charities Division$70 a yearannual — due the last day of the month the entity was formed or registered2026-09-03
Washington State Business LicenseWashington State Department of Revenue, Business Licensing Service$50 to open, plus each endorsement's own fee; $5 a year to renewannual — one expiration date governs every endorsement on the license2026-09-03

Fees shown as a range or formula are set that way by the issuing agency — we do not average them into a single number.

How much does it actually cost to permit a contractor or trade in King County?

There is no single figure, and any site quoting one is rounding away the part that matters. Of the 17 records listed for a contractor or trade in King County, WA, 2 apply to every business of this type and 15 are conditional. Adding every fee on the page together would overstate what most operators pay, because it would include permits they never need.

Of the 2 that always apply, 2 carry a flat fee, coming to $200.20. That is a floor, not a total. 4 of the 17 are charged as a range or a formula set by the issuing agency, and 4 have no fee published at all.

The other 4 variable fees belong to permits that apply to every type of business here; their formulas are set out on the King County permits page and the WA state page.

Which offices issue these permits in King County?

Permits for a contractor or trade in King County, WA come from 5 separate offices: King County Department of Local Services, Permitting Division, Public Health – Seattle & King County, Environmental Health Services (pet business, water recreation, on-site sewage, and plumbing & gas piping programs), Washington Secretary of State, Corporations and Charities Division, Washington State Department of Revenue, Business Licensing Service, Washington State Department of Labor and Industries. No single office issues them all, which is why an opening means filing in several places rather than one.

What does a contractor or trade need in King County that other businesses do not?

6 of the 7 permits particular to a contractor or trade here apply to no other business type we cover in King County: Contractor Registration — State Labor & Industries Applies (King County), Heating, Air-Conditioning, Ventilation Systems and Equipment Installers License, Tank Removal Contractor Annual Certification and 3 more.

Home Occupation — Allowed Under Zoning Standards (King County)

No fee applies. King County charges no permit fee for a home occupation in unincorporated King County; it is allowed as an accessory use if it meets zoning standards, and which uses are barred depends on the zone. In the R, UR, NB, CB and RB zones (KCC 21A.30.080.E), a home occupation may not be automobile, truck or heavy-equipment repair, auto body work or painting, a veterinary clinic, recreational cannabis processing, production or retail, or a winery, brewery, distillery or remote tasting room. In the A, F and RA zones (KCC 21A.30.085.J) the barred list is shorter and different: hotels, motels or other lodging; dry cleaning; automotive towing, wrecking or tow-in lots; recreational cannabis; and winery, brewery, distillery or remote tasting-room uses — auto repair and veterinary clinics are NOT barred as home occupations in these agricultural, forest and rural zones. The two zone groups also differ on the operating standards themselves: the R/UR/NB/CB/RB zones require indoor-only operation, one non-resident employee, appointment-only patron service and one business vehicle, while the A/F/RA zones allow limited outdoor operation, up to three non-resident employees, no appointment-only restriction and two to four vehicles; both cap floor area devoted to the occupation at 20% of the dwelling. A use barred outright as a home occupation may still be reachable through a home industry conditional use permit (see that record). Regulated activities such as massage still need their own Title 6 license, and food businesses still need a Public Health permit regardless of zone.

Contractor Registration — State Labor & Industries Applies (King County)

No fee applies at the county level. RCW 18.27.020(1) requires every contractor to register with the Washington State Department of Labor & Industries, and RCW 18.27.020(2)(a) makes it a gross misdemeanor to advertise, bid or perform work as a contractor without that registration. King County Code §16.32.275 itself directs plumbers and contractors to 'comply with all applicable state or local rules and regulations concerning plumber certification and contractor registration' rather than adding a county credential of its own, and L&I also issues electrical permits in unincorporated King County. The only county-level contractor credentials are the $50-a-year HVAC installers license (KCC 6.32) and the $183 annual tank-removal contractor certification (KCC 27.10.580.C), both listed separately. A contractor building in the unincorporated area obtains building, mechanical and fire permits from King County Permits, plumbing and gas permits from Public Health (in Seattle, Clyde Hill and unincorporated King County only), and each city's own permits elsewhere.

Heating, Air-Conditioning, Ventilation Systems and Equipment Installers License

King County Code sets a license fee of $50 a year, expiring each June 30, for any business selling, installing, altering or repairing heating, air-conditioning, ventilation or exhaust equipment in unincorporated King County, backed by a $1,000 surety bond under KCC §6.32.030. The chapter is codified in Title 6 and in force in the current text, but the County's own current business-license page and its 2026 Fee Guide 10 do not list this license among those it processes today. Ask King County Permits, (206) 296-6600, whether it is actively issued before applying or before assuming a contractor holds it. It is in addition to state contractor registration (Labor & Industries) and the mechanical permit, which is priced under the valuation-based building permit fees.

Tank Removal Contractor Annual Certification

Contractors who remove or decommission fuel tanks in unincorporated King County — the County's application describes the scope as fuel tanks generally and requires state licensing plus ICC UST-certified staff, not only residential heating-oil tanks — are certified annually by King County Permits; the fee is the minimum inspection-fee amount set in KCC §27.10.320.A.1, $183 in 2026. This is not the County's only Title 6 or Title 27 contractor credential: heating, air-conditioning and ventilation installers separately need the $50-a-year HVAC installers license under KCC 6.32 (listed separately), so tank-removal certification should not be treated as the sole county-level contractor credential. General contractor registration itself remains a state Labor & Industries requirement. This is the 2026 fee schedule; King County Code sets a lower fee ($160) effective January 1, 2027, unless the Council adopts a new fee ordinance first (one was due to the Council by October 1, 2026). Confirm the current fee with King County Permits, (206) 296-6600, after January 2027.

Contractor Registration

Washington registers contractors rather than licensing them, and there is no competency exam for either a general or a specialty registration — the gate is money. A $30,000 bond for a general contractor or $15,000 for a specialty one, both doubled on 1 July 2024 from $12,000 and $6,000, so older figures are wrong; plus $200,000 of public liability and $50,000 property damage cover, or $250,000 combined. Judgments involving single-family dwellings in the past five years push the bond up to $90,000. A general contractor may hire subcontractors across trades while a specialty contractor may work only in its own registered specialty and may not subcontract at all. Working unregistered is a gross misdemeanour. Registration is not one of the endorsements the statewide business license carries.

Electrical Contractor License

One price covers a general electrical contractor and every specialty — the rule does not distinguish them, and holding several specialties needs only one fee and one bond. Completing the renewal fully online saves $47.70. A $4,000 bond is required, along with $20,000 property, $50,000 single-injury and $100,000 multiple-injury cover, and the business must designate a certified master electrician or administrator whose own credential is separately priced. The current schedule took effect on 1 July 2026 and these fees are revised on an annual July cycle, so check the date on anything you read.

Plumbing Contractor License

This is the single most out-of-date thing in circulation about Washington contracting. Since 1 July 2021 plumbing contractors have held a standalone license and are expressly exempt from the general contractor registration chapter — so material describing Washington plumbers as specialty contractors is publishing pre-2021 law. The bond is $6,000 and the insurance limits are $50,000 property, $100,000 for one person and $200,000 for more, all higher than the electrical contractor's. Individual journey level, residential specialty and residential service certificates are $242.70 for three years, and a trainee certificate is $60 a year. As with electrical, the current schedule dates from 1 July 2026.

The other 5 local permits in the tables apply to every type of business in King County, WA; what each one involves is set out on the King County permits page. The 5 state-level registrations apply to every type of business across WA and are covered on the WA state page.

How does a contractor or trade compare with other businesses in King County?

The closest match is a childcare centre, which shares 1 of these permits. A contractor or trade also needs Contractor Registration — State Labor & Industries Applies (King County), Heating, Air-Conditioning, Ventilation Systems and Equipment Installers License, Tank Removal Contractor Annual Certification and 3 more. A childcare centre needs Fire Code Operational Permit (annual, unincorporated King County), Conditional Use Permit, Zoning Variance and 2 more, which a contractor or trade does not.

Permits particular to each business type in King County, WA, compared with a contractor or trade
BusinessIts own permitsShared with a contractor or tradeOnly a contractor or trade needsOnly it needs
Childcare centres6165
Fitness studios7166
Salons and barbers8167
Retail stores9168
Auto repair shops8078
Coffee shops7077
Food trucks6076
Restaurants100710
Veterinary clinics7077

Sources

Every figure for the permits explained on this page was read from one of these government pages on the date shown. Sources for the permits that apply to every type of business are listed on the King County permits page and the WA state page. Confirmed by Editorial Team.

  1. King County Code Title 21A, 'Zoning,' UPDATED September 9, 2026King County Council Clerk · primary source · retrieved 2026-09-27
  2. Business licenses (Permitting Division) — the County's own list of every county business license it issuesKing County Dept. of Local Services · primary source · retrieved 2026-09-27
  3. RCW 18.27.020, contractor registration required and penalty for unregistered workWA Code Reviser · primary source · retrieved 2026-09-27
  4. King County Code index page (Titles 1-28)King County Council · primary source · retrieved 2026-09-27
  5. King County Code Title 16, 'Building and Construction Standards,' UPDATED June 5, 2026 (§16.02 administration; certificate of occupancy §§16.02.470-.540; fees §16.02.400; ch. 16.32 Plumbing Code)King County Council Clerk · primary source · retrieved 2026-09-27
  6. King County Code Title 27, 'Development Permit Fees,' UPDATED March 2, 2026 — chs. 27.06, 27.10 (Ordinance 20021, November 18, 2025; §§2-33 expire January 1, 2027)King County Council Clerk · primary source · retrieved 2026-09-27
  7. King County Code Title 6, 'Business Licenses and Regulations,' UPDATED September 8, 2026King County Council Clerk · primary source · retrieved 2026-09-27
  8. Fire and special event permit processKing County Dept. of Local Services · primary source · retrieved 2026-09-27
  9. Washington Labor and Industries — contractor registration fee, bond and insurance requirementsWashington State Department of Labor and Industries · primary source · retrieved 2026-09-03
  10. WAC 296-200A-035 — two-year contractor registration periodWashington State Department of Labor and Industries · primary source · retrieved 2026-09-03
  11. WAC 296-46B-909 — electrical contractor license feesWashington State Department of Labor and Industries · primary source · retrieved 2026-09-03
  12. WAC 296-400A-045 — plumbing contractor license feesWashington State Department of Labor and Industries · primary source · retrieved 2026-09-03
  13. RCW 18.106.400 — the standalone plumbing contractor license and its exemption from contractor registrationWashington State Legislature · primary source · retrieved 2026-09-03

Related

Commercial Compliance Hub publishes information, not legal advice. Requirements change — confirm anything you rely on with the issuing agency before you file.