Washington Plumbing Specialty Contractor License

The Plumbing Specialty Contractor License allows you to do the following work:

• Install, alter, repair and renovate:
  • All potable water pipes
  • Building supply pipes
  • Distribution pipes
  • All plumbing fixtures and traps
  • All drainage and vent pipes
  • All building drains and building sewers, including their respective:
    • Joints
    • Connections
    • Devices
    • Receptors
    • Appurtenances within the property lines of the premises and shall include:

      • Potable water piping
      • Potable water treating or using equipment
      • Medical gas and medical vacuum systems
      • Liquid and fuel gas piping
      • Water heaters
      • Hydronic heating systems and vents

Includes solar heating equipment attached to potable water systems. Plumber certification is required for work within a building.

How to Get the Plumbing Specialty Contractor’s License in Washington?

1. Determine the business type and register with the Department of Revenue:
   • If setting up a sole proprietor or partnership, determine the business name
   • If starting a Limited Liability Company (LLC) or a Corporation, refer to the Secretary of State for information on how to incorporate the business
2. Complete and get a Washington Continuous Contractor Surety Bond for the required amount
3. Purchase a general liability insurance policy for the required amount
4. Fill out an Application for Contractor Registration with notarized signatures. If unsure of how to correctly fill out the application form, the Washington State Department of Labor & Industries offers help with the application and business registration to those who visit their local offices
5. Gather all the previous documents and send them with the registration fee to:
   Washington State Department of Labor & Industries
   Contractor Registration
   P.O. BOX 44450
   Olympia, WA 98504-4450
   It is also possible to visit a local office to deliver all the documents and fees
6. Expect a registration card from the Washington State Department of Labor & Industries after the application is processed
7. Note that once the business has been registered, it will be listed in the Washington State Department of Labor & Industries Verify a Contractor, Tradesperson, or Business website