HVAC Contractor Permit Requirements in Seattle, WA

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)

   $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

   Free·Immediate (online application)

   Free

   Immediate (online application)

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

   Washington has no separate HVAC contractor license or exam. HVAC/mechanical contractors register as specialty contractors with the Department of Labor & Industries under RCW 18.27, the same as other trades. Registration requires a continuous surety bond or assignment of savings, general liability insurance, workers' compensation coverage if you have employees, and a UBI number. A specialty contractor may work only in the registered specialty and may not hire subcontractors; registering as a general contractor removes that limit but raises the bond. Any electrical work performed as part of HVAC installation requires a separate L&I electrical contractor license and certified electricians.

   Official government source

   $150.20 registration fee (same amount to renew; $70.90 to reinstate a suspended registration), plus a continuous contractor surety bond or assignment of savings - $30,000 for general contractors, $15,000 for specialty contractors - and general liability insurance of $200,000 public liability / $50,000 property damage or a $250,000 combined single limit. Bond premiums vary by surety.·Applications mailed to L&I currently take 3-4 weeks to process and activate; applying in person at an L&I office is faster. The registration card arrives about 2 weeks after activation.

   $150.20 registration fee (same amount to renew; $70.90 to reinstate a suspended registration), plus a continuous contractor surety bond or assignment of savings - $30,000 for general contractors, $15,000 for specialty contractors - and general liability insurance of $200,000 public liability / $50,000 property damage or a $250,000 combined single limit. Bond premiums vary by surety.

   Applications mailed to L&I currently take 3-4 weeks to process and activate; applying in person at an L&I office is faster. The registration card arrives about 2 weeks after activation.

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 (air conditioning, heat pump, refrigeration, ventilation) specialty electrical licence where electrical work is involved, plus a Seattle business licence.

   Official government source

   Based on the value of construction plus hourly review at the SDCI hourly rate of $292 (2026 Fee Subtitle), plus a technology fee; kitchen hood exhaust systems add a fire review fee. About 75 percent is due at intake.·SDCI advises planning for 9 weeks from application to permit issuance; initial review targets are 2 weeks for simple projects and 4 weeks for complex ones, and simple work can get a mechanical subject-to-field-inspection permit within 24 hours. Application intake typically takes 2-3 weeks.

   Based on the value of construction plus hourly review at the SDCI hourly rate of $292 (2026 Fee Subtitle), plus a technology fee; kitchen hood exhaust systems add a fire review fee. About 75 percent is due at intake.

   SDCI advises planning for 9 weeks from application to permit issuance; initial review targets are 2 weeks for simple projects and 4 weeks for complex ones, and simple work can get a mechanical subject-to-field-inspection permit within 24 hours. Application intake typically takes 2-3 weeks.

Official Sources

• Seattle SDCI Permits
• Washington L&I — Contractor License

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