Gas line work
Who may work on gas piping in Seattle and King County
This page is about hiring for gas line work. If you smell gas now, stop reading and get out of the building.
If you smell gas, do this first
- Leave the area right away. If you are indoors, get everyone out of the building. (PSE)
- Once you are a safe distance away, call PSE at 1-888-225-5773 or call 911. Don't use a landline phone inside, which may cause a spark. (PSE) (PSE)
- Don't flip any switch on or off, or do anything else that could make a spark. (PSE)
- PSE says it sends a technician to check that the area is safe, at no charge. (PSE)
Our gas leak first steps page lists the other warning signs. Hire for repairs only after the utility clears the scene.
What Washington law lists
The state plumber certificate law defines plumbing as work on potable water, liquid waste and medical gas piping systems inside a building. Fuel gas piping is not in that definition. (RCW 18.106.010)
L&I's plumbing contractor specialty includes liquid and fuel gas piping, and its text adds that plumber certification is required for work within a building. (WAC 296-200A-016(42))
The HVAC/R and the wood, pellet and gas stove specialties also include gas piping in their scope. (WAC 296-200A-016)
King County and Seattle rules
- Property owners may install gas piping on property they own. (King County)
- If you pay someone for gas piping work, the installer must be a registered contractor or work for one. Public Health Seattle and King County issues these permits for Seattle and unincorporated King County. (King County)
- Inside Seattle only, the installer must be the property owner or hold a Seattle Gas Piping Mechanic License. (King County)
- That Seattle license covers gas piping from the meter to the appliance or point of use, and it is renewed each year. (Seattle SDCI)
- To qualify, a mechanic needs 12 months of full-time gas piping experience, or 6 months plus a board-approved class, or a valid plumber's license, and must pass an open-book exam with at least 70 percent, then obtain the license within 90 days of passing the test. (Seattle SDCI)
- Seattle's 2026 fee for the Gas Piping Mechanic License is $139 a year, and each license exam costs $62.55. (Seattle 2026 Fee Subtitle, read Oct 18, 2026)
- King County's permit types include a homeowner gas permit for work the homeowner does alone, and residential gas permits used by licensed plumbing or general contractors. (King County)
- The 2026 King County gas piping permit fee is $137 plus $27 per outlet. (King County 2026 fees, read Oct 18, 2026)
Questions before gas work starts
- In Seattle: what is your Gas Piping Mechanic License number?
- Are you a registered contractor, or employed by one? I will check on L&I Verify.
- Who buys the gas piping permit, and which permit type is it?
- Is the gas work in the written price, or on its own bill?
Next
Read what a Washington plumber license covers or when a water heater or fixture needs a permit.
Sources
We read each source on October 18, 2026. Rules and prices change, so check the linked page before you rely on a number.
- PSE: Detect a gas leak
- PSE: Report a gas emergency
- RCW 18.106.010, plumbing definitions
- WAC 296-200A-016, contractor specialties
- Public Health Seattle and King County: Hire a registered contractor
- Seattle SDCI: Gas piping mechanic license
- Seattle SDCI 2026 Fee Subtitle (PDF)
- King County: Plumbing and gas permit types (PDF)
- Public Health Seattle and King County: Plumbing and gas piping fees, 2026 (PDF)
- Washington L&I: Verify a Contractor, Tradesperson or Business
Written by the Puget Sound Emergency Plumbers team. We list businesses; we do not employ, bond or insure them. Spot a mistake? Use the claim page to tell us.