Local rules & permits
Contractors must register with L&I; no state mold license
Washington requires all construction contractors to register with the Department of Labor & Industries (L&I) before doing repair or restoration work; general contractors must post a $30,000 bond (specialty contractors $15,000) and carry liability insurance. Washington does not license or certify mold assessment or remediation — the Department of Health states there are no specific certification requirements for mold/water-damage restoration, so 'mold specialist' is not a regulated title. Homeowners should verify a contractor is registered, bonded and insured through L&I's Verify a Contractor tool before hiring.
Washington State Department of Labor & Industries
lni.wa.gov/licensing-permits/contractors/register-as-a-contractor
Source: lni.wa.gov