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 | $189.80 |
| Exam Fee | $80 |
| Initial License Fee | $227.90 |
| Est. Initial Total | $497.70 |
Related & additional fees
Separate or ongoing costs — not included in the estimate above.
| Plumber trainee certificate | $56.40 |
| Plumbing contractor license | $139.10 |
| Plumbing contractor surety bond | $6,000 |
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
Recommended exam prep
Formal prep pays for itself against a $100+ retake. Many states examine contractors on two separate papers — the trade exam and a business and law exam — so we list the course covering both first, with trade-specific depth after.
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Mometrix · SponsoredContractor License Online Study CourseFull online prep course covering the trade and business-and-law exams — video lessons, practice questions, and a study plan built for a first-try pass.See the course →
Mometrix · SponsoredPlumber's Exam Secrets Study GuideCovers plumbing code, systems, and installation for the journeyman and master plumber exams — organized topic reviews plus practice questions for a first-try pass.See the study guide →
Mometrix · SponsoredPlumber's Exam FlashcardsPortable flashcards for the high-frequency plumber-exam topics — a cheaper add-on for drilling code references and terms on the go.See the flashcards →Set up the business before you apply in Washington
Most states license the company as well as the person, so the application usually asks for an LLC or corporation and a registered agent in Washington. Northwest forms the entity and acts as your registered agent — a flat fee, no upsell funnel.
Some links below are affiliate links. If you buy through them we may earn a commission at no extra cost to you.
Form an LLC with Northwest→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
You're licensed in Washington as a plumber — the next 30 days
Most of the steps below are required before your first paid job; the order is the order the state and its counties will ask for them.
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Form the business and get an EIN.
The Department of Labor & Industries issues the Plumber Certification (Journey Level PL01); the business that invoices Washington customers is a separate decision. A sole proprietorship is the default, an LLC keeps business liability off your personal assets, and either needs an EIN before the first payroll. Settle it before the license number goes on an estimate.
Post the bond.
Washington requires a $6,000 surety bond. 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. How contractor bonds work→
Carry the insurance the license requires.
Washington requires general liability insurance for this license. Plumbing contractors need $250,000 combined single limit general liability insurance. Workers comp through WA State Fund (L&I) required with employees. Plumbing contractor license is separate from general contractor registration. Contractor insurance requirements→
Register locally.
Some cities require additional plumbing permits. Seattle has supplemental plumbing requirements.
Set up quoting, scheduling and invoicing before the first call.
Your first customers will ask for a written estimate and expect to pay by card on site. Most one-truck plumber businesses run that on field-service software; Housecall Pro is the one we link because it is built for this size of company and this link carries 20% off your first 12 months. Start a free trial of Housecall Pro→
Keep the license.
Renewal is every 3 years at $227.90. Continuing education: 24 hours every 3 years.
Other licenses in Washington
- General Contractor license in Washington
Statewide registration, not a license · $150.2 in fees · L&I
- Electrician license in Washington
Statewide license required · $280.2 in initial government fees · L&I
- HVAC Technician license in Washington
Statewide license required · $313.7 in initial government fees · L&I
- Roofing Contractor license in Washington
Statewide registration, not a license · $141.1 in fees · L&I
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.
Next steps
You know the requirements for plumbers in Washington— here's how to actually pass and apply.
Data last verified: 2026-04-02 | Source: L&I