HVAC Contractor Permit Requirements in Seattle, WA

Complete permit and license guide for starting a hvac contractor in Seattle, King County, Washington.

Updated 2026-03-15 4 stops $700–$2,500 est. 8–14 weeks to obtain all licenses
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Not legal advice. Requirements may change — always verify with your local government authority before applying. This guide was compiled from public and official sources (last updated ) and has not yet been independently source-verified — confirm each requirement before acting on it.

Federal — start here

2 stops

  1. EPA Section 608 Technician Certification

    Federal law requires all HVAC technicians who purchase or handle refrigerants to be certified under EPA Section 608 of the Clean Air Act. Certification is available in Type I (small appliances), Type II (high-pressure), Type III (low-pressure), and Universal categories. Certification is obtained through an EPA-approved testing organization such as ESCO Institute or NATE.

    Official government source

    $20–$60 (exam fee)1–2 weeks (exam scheduling)

  2. EIN (Employer Identification Number)

    Required if you have employees or operate as an LLC or corporation. Free from the IRS.

    Official government source

    FreeImmediate (online application)

State of Washington

1 stop

  1. Washington State Department of Labor and Industries — HVAC Contractor License

    Washington requires HVAC contractors to hold an Air Conditioning and Heating (ACH) specialty contractor license from the Department of Labor and Industries. A licensed journeyman must be on staff. Exam, $6,000 bond, and workers' compensation coverage required.

    Official government source

    $200 application fee + $75 exam fee + $6,000 bond (~$50–$100/year)6–10 weeks

City of Seattle / King County

1 stop

  1. City of Seattle — Mechanical Permit

    Seattle requires a mechanical permit for HVAC installation from the Seattle Department of Construction and Inspections (SDCI). Contractors must hold a valid Washington state ACH license and a Seattle business license.

    Official government source

    $100–$600 per project2–6 weeks

Terminus

Open for business — est. $700–$2,500 · 8–14 weeks to obtain all licenses

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Official Sources

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