Plumber License Requirements in Washington
| Licensing Authority | Department of Labor & Industries (L&I) |
| License Type | Plumber Certification (Journey Level PL01) |
| Experience Required | Journey Level (PL01): 8,000 hours (minimum 4 years) under supervision of a certified journey level plumber, with at least 4,000 hours (2 years) in commercial or industrial installations. Residential specialty: 6,000 hours (3 years). Residential service: 4,000 hours (2 years). |
| Education Substitute | Completion of a registered plumbing apprenticeship program satisfies experience requirements. Military plumbing experience may be accepted as equivalent. |
| Exam Required | Yes — Journey Level Plumber Exam - Part 1 + Journey Level Plumber Exam - Part 2 + Journey Level Plumber Exam - Part 3 |
| Bond Required | Yes — $6,000 |
| Insurance | General liability: required. Workers comp: required with employees |
| Continuing Education | 24 hours 3 years |
| Processing Time | 2-4 weeks for certification; trainee certificate mailed in 2-4 weeks |
Fee Breakdown
| Application Fee | $189.8 |
| Exam Fee | $80 |
| Initial License Fee | $227.9 |
| Plumber trainee certificate | $56.4 |
| Plumbing contractor license | $139.1 |
| Plumbing contractor surety bond | $6000 |
| Est. Initial Total | $6,693.2 |
Renewal: $227.9 every 3 years
Exam Requirements
Journey Level Plumber Exam - Part 1
Journey Level Plumber Exam - Part 2
Journey Level Plumber Exam - Part 3
Exam provider: PSI
License Tiers
PL01 - Journey Level Plumber
8,000 hours (4+ years) as plumber trainee under certified journey level plumber, with at least 4,000 hours in commercial/industrial.
Exam: Required
Residential Specialty Plumber
6,000 hours (3+ years) working in specialty under supervision of certified residential or journey level plumber.
Exam: Required
Residential Service Plumber
4,000 hours (2+ years) as trainee; first 2,000 hours under direct supervision of journey level or residential specialty plumber.
Exam: Required
Plumber Trainee
No experience required to start. Must work under supervision of certified plumber.
Exam: Not required
License Reciprocity
This state has reciprocity agreements with 1 state. View full reciprocity details — You may be able to skip the trade exam if you hold a valid license from one of these states.
Notes
- Journey Level exam is closed-book with 3 parts (150 total questions, 4.5 hours total)
- Must complete 16 hours of CE prior to testing (minimum 4 hours electrical)
- CE requirements (effective July 2021): 12 hours Uniform Plumbing Code, 4 hours industry-related electrical, 8 hours elective (Code, IRE, or IRP)
- Plumber trainee must complete 8 hours CE per year
- Plumbing contractor license ($139.10 for 2 years) is separate from individual plumber certification
- Plumbing contractor must have a designated certified plumber on staff
- Certifications expire every 3 years on licensee's birthday
Frequently Asked Questions
Do I need a plumber license in Washington?
Yes, Washington requires a statewide plumber license through the Department of Labor & Industries.
How much does a plumber license cost in Washington?
The estimated initial cost is $497.7, including application, exam, and license fees. A $6,000 surety bond is also required.
What experience do I need for a plumber license in Washington?
Journey Level (PL01): 8,000 hours (minimum 4 years) under supervision of a certified journey level plumber, with at least 4,000 hours (2 years) in commercial or industrial installations. Residential specialty: 6,000 hours (3 years). Residential service: 4,000 hours (2 years). Education substitute: Completion of a registered plumbing apprenticeship program satisfies experience requirements. Military plumbing experience may be accepted as equivalent.
What exams are required for a plumber license in Washington?
You must pass the Journey Level Plumber Exam - Part 1 and Journey Level Plumber Exam - Part 2 and Journey Level Plumber Exam - Part 3 exams. A passing score of 70% is required. Exams are administered by PSI.
Do I need a bond for a plumber license in Washington?
Yes, a $6,000 surety bond is required. Plumbing contractors must file a $6,000 surety bond (separate from general contractor registration bond). Individual certified plumbers who are employees do not need a bond.
Does Washington have plumber license reciprocity?
Yes, Washington has reciprocity agreements with 1 state that may apply to plumbers. Licensed contractors from these states may be eligible to skip certain exams or have an expedited application process.
How long does it take to get a plumber license in Washington?
Processing time is typically 2-4 weeks for certification; trainee certificate mailed in 2-4 weeks after submitting a complete application.
Is continuing education required for plumbers in Washington?
Yes, 24 hours per 3 years is required for license renewal.
Data last verified: 2026-04-02 | Source: L&I