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. 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.
Data last verified: 2026-04-02 | Source: L&I