How much does an Plumbing license cost in Washington?

Per WAC 296-400A-045 (Department of L&I): Plumbing contractor initial/renewal/re-registration: $139.10 (2-year cycle). Initial identification or change in designated plumber: $50.00. Examination application for journey level, residential specialty, residential service, backflow certification, or domestic pump: $189.80. Reciprocity application: $189.80. Trainee certificate: $56.40 (1-year or when hours updated). Temporary permit: $94.20 (120 days). Journey level, residential specialty, or residential service certificate renewal or 1st card: $227.90 (3 years). Domestic pump specialty certificate renewal: $228.00 (3 years). Backflow assembly maintenance and repair specialty certificate renewal: $157.20 (3 years). Medical gas endorsement application: $69.80. Medical gas endorsement renewal: $156.70 (3 years). Reinstatement of a plumbing contractor license: $69.50. Reinstatement fee for residential and journey level certificates: $304.70. Reinstatement fee for backflow certificates: $175.20. Reinstatement fee for domestic pump: $456.30. Replacement fee: $25.60. Unsupervised trainee endorsement: $40.70. Inactive status fee: $40.70. Certified letter fee / verification of licensure: $40.70. Service of process fee: $55.00. Document copy: $2.40/page (max $37.40). Continuing education new course fee: $246.70 (3-year). Continuing education renewal course fee: $123.10 (3-year). Continuing education classes: $14.90/hour (or $9.90/hour for correspondence/internet).

How often do you renew an Plumbing license in Washington?

Plumbing contractor: 2-year cycle ($139.10). Plumber certificates (journey level, residential, residential service, specialty): 3-year cycle. Medical gas endorsement: 3-year renewal. Trainee certificate: 1-year or when hours are updated (per WAC 296-400A-045).

Does a Washington Plumbing license transfer to other states?

Per RCW 18.106.155 and WAC 296-400A-045: A reciprocity application is $189.80; reciprocity is only allowed for applicants applying work experience toward certification that was obtained in state(s) with which the department has a reciprocity agreement. The reciprocity application is valid for one year (per WAC 296-400A-045).

How to Get a Plumbing License in Washington (2026 Guide)

Navigating plumbing licensure in Washington State is crucial, as the Department of Labor & Industries (L&I) strictly requires certification for anyone performing plumbing work, ranging from trainees to specialty plumbers and contractors. This guide provides the exact, sourced steps and requirements to get licensed, ensuring you meet all state regulations for this well-paid trade.

Do You Need a Plumber License in Washington?

Yes, a state-issued certificate or license is required to perform plumbing work in Washington. The Washington State Department of Labor & Industries (L&I) regulates and certifies individual plumbers and licenses plumbing contractors who employ them, as established in RCW 18.106. This requirement ensures that all plumbing work meets the standards of the Uniform Plumbing Code (UPC) adopted by the state, protecting public health and safety.

Washington Plumber License Tiers and Classifications

The Washington Department of Labor & Industries issues several types of plumber certifications and a specific license for plumbing businesses. The primary classifications include Plumber Trainee, Specialty Plumber, Journey Level Plumber, and the Plumbing Contractor license for business entities.

Plumber Trainee

A Plumber Trainee certificate is the starting point for individuals entering the trade. This certificate allows you to work and gain the necessary experience under the direct supervision of a certified Journey Level or Specialty Plumber. Trainees must register with L&I to have their work hours legally tracked and applied toward future certification.

Specialty Plumber

A Specialty Plumber certificate authorizes work in specific, limited areas of the plumbing trade. According to WAC 296-400A, Washington recognizes several specialties, including:

Domestic Pump
Residential Service
Backflow Assembly Maintenance and Repair
Medical Gas Piping Installation (This is an endorsement added to a Journey Level certificate)

Each specialty has distinct experience requirements and a focused scope of work.

Journey Level Plumber

A Journey Level Plumber certificate authorizes the holder to perform a full scope of plumbing work. Per RCW 18.106.040, this includes installing, maintaining, and repairing pipes, fixtures, and other plumbing equipment for water distribution and sanitation systems in residential, commercial, and industrial settings.

Plumbing Contractor

A Plumbing Contractor license is a business license required for any company that employs plumbers and contracts to perform plumbing work. To obtain this license, the business must register with L&I and designate a certified Journey Level or Specialty Plumber who is responsible for the work performed by the company.

Washington Plumber License Requirements: Step-by-Step

Follow these steps to earn your Washington plumber certification or contractor license.

Step 1: Meet Experience or Education Requirements

Per RCW 18.106.040, you must provide written evidence of meeting specific work experience or educational qualifications.

Journey Level Plumber: Four or more years of experience working under the direct supervision of a certified Journey Level Plumber OR completion of a plumbing trade course in the U.S. armed services or at a school accredited by the Washington workforce training and education coordinating board.
Specialty Plumber: At least three years of experience in the specific specialty under the supervision of a certified Journey Level Plumber or a certified plumber in that specialty.
Residential Service Plumber: Two or more years of experience under the supervision of a certified Journey Level Plumber, certified Specialty Plumber, or certified Residential Service Plumber.

Step 2: Prepare for and Pass the Plumber Certification Exam

An exam is required to obtain a Journey Level, Residential Service, or other Specialty Plumber certificate. The Washington Department of Labor & Industries (L&I) administers the Plumber Certification program and coordinates exams with a state-authorized testing contractor. Exam topics generally cover the Uniform Plumbing Code (UPC), state-specific rules, and practical knowledge of the trade.

The passing score and specific content for each exam are published by L&I; confirm the current details in the exam candidate bulletin before scheduling your test.

Step 3: Gather Supporting Documentation

Prepare a complete application package with all required documents. This typically includes:

A completed application form for the specific certificate.
Written proof of qualifying work experience or education.
Valid identification.
Payment for all applicable fees.

Step 4: Submit Your Application to L&I

Submit your completed application and supporting documents to the Department of Labor & Industries Plumber Certification program. Applications can typically be submitted by mail or online. Ensure you pay the required examination application fee at the time of submission.

Step 5: Obtain Required Insurance and Bonding (Plumbing Contractors)

Plumbing contractors must secure a surety bond and liability insurance before their license will be issued.

Surety Bond: Per WAC 296-400A-012, a plumbing contractor must have a continuous surety bond of $6,000.
Liability Insurance: Per RCW 18.106.420, contractors must carry general liability insurance with coverage of at least $200,000 for injury or death to one person, $400,000 for injury or death to more than one person, and $100,000 for property damage.

Step 6: Receive Your Washington Plumber License or Certificate

Once L&I has approved your application, verified your experience, and received notice that you have passed the exam, they will issue your plumber certificate. For contractors, the license is issued after all registration, bonding, and insurance requirements are met.

Washington Plumber License Costs and Fees

The primary fee for a journey level or specialty plumber exam application is $189.80, as set by the Department of Labor & Industries in WAC 296-400A-045. A comprehensive schedule of fees is maintained by the department.

Plumbing Contractor License (Initial/Renewal): $139.10 (2-year cycle)
Designated Plumber (Initial or Change): $50.00
Examination Application (Journey, Specialty, Residential, Backflow, Pump): $189.80
Reciprocity Application: $189.80
Trainee Certificate: $56.40 (1-year or when hours are updated)
Temporary Permit: $94.20 (valid for 120 days)
Certificate Renewal (Journey, Residential Specialty, Residential Service): $227.90 (3 years)
Domestic Pump Specialty Renewal: $228.00 (3 years)
Backflow Assembly Specialty Renewal: $157.20 (3 years)
Medical Gas Endorsement Application: $69.80
Medical Gas Endorsement Renewal: $156.70 (3 years)
Reinstatement Fee (Contractor): $69.50
Reinstatement Fee (Journey/Residential Certificates): $304.70
Reinstatement Fee (Backflow Certificates): $175.20
Reinstatement Fee (Domestic Pump): $456.30
Replacement Certificate/License: $25.60
Continuing Education Course Fee: $14.90 per hour (or $9.90 per hour for correspondence/internet courses)

Washington Plumber License Renewal and Continuing Education (CE)

Plumber certificates in Washington must be renewed every three years. According to WAC 296-400A-028, certified plumbers must complete 24 hours of approved continuing education during each renewal cycle to be eligible. This must include at least 16 hours on the Uniform Plumbing Code (UPC) and up to 8 hours on industry-related electrical standards.

Plumbing Contractor License Renewal: Every 2 years.
Plumber Certificate Renewal (Journey/Specialty): Every 3 years.
Medical Gas Endorsement Renewal: Every 3 years.
Trainee Certificate Renewal: Every year or when work hours are updated.

Washington Plumber License Reciprocity

Washington allows for plumber license reciprocity with states that have established a formal agreement with the department, per RCW 18.106.155. The reciprocity application fee is $189.80 and is valid for one year. This process allows plumbers certified in a reciprocating state to potentially bypass some examination or experience requirements. The specific states with active agreements are subject to change; applicants should confirm the current list of reciprocating states directly with the L&I Plumber Certification program before applying.

Washington Plumber Licensing Board and Contact Information

The regulatory body for plumbers in Washington is the Department of Labor & Industries (L&I).

Agency: Washington State Department of Labor & Industries (L&I)
Program: Plumber Certification
Website: https://www.lni.wa.gov/licensing-permits/plumbing/
Contact Information: Contact details, including mailing addresses and phone numbers, are available on the L&I website.

Frequently Asked Questions

Do you need a license to do plumbing work in Washington?

Yes, Washington state law (RCW 18.106) requires that any individual performing plumbing work must hold a valid certificate from the Department of Labor & Industries (L&I). Businesses that offer plumbing services must be licensed as plumbing contractors.

How do I get a Washington Journeyman Plumber License?

To get a Journeyman Plumber certificate in Washington, you must document at least four years of supervised work experience or equivalent accredited education, submit an application to L&I with the $189.80 exam fee, and pass the state-administered journeyman plumber certification exam.

How do I get a Washington Residential Plumber License?

To obtain a Residential Service Plumber certificate, you must show at least two years of qualifying supervised experience, apply to L&I, pay the $189.80 exam application fee, and pass the residential service plumber exam.

What experience is required for a Washington Journeyman Plumber license?

You need a minimum of four years of experience working under the direct supervision of a certified journey level plumber. Alternatively, you can qualify by completing a course of study in the plumbing trade through the U.S. armed services or at a school accredited by the state's workforce training and education coordinating board.

How much does a plumber license cost in Washington?

The initial cost varies by license type. The examination application fee for a Journey Level or Specialty Plumber certificate is $189.80. The initial license for a Plumbing Contractor is $139.10 for a two-year period. Additional fees apply for certificate issuance, renewals, and endorsements.

Does Washington require a plumbing contractor to be bonded?

Yes, all plumbing contractors in Washington must post a continuous surety bond of $6,000 with the Department of Labor & Industries, as required by WAC 296-400A-012.

What continuing education is required to renew my Washington plumber license?

To renew a plumber certificate, you must complete 24 hours of approved continuing education every three years. Per WAC 296-400A-028, this must include at least 16 hours focused on the Uniform Plumbing Code (UPC).

Does Washington have plumber license reciprocity with other states?

Yes, Washington has reciprocity agreements with some other states. An applicant whose experience was gained in a reciprocating state may apply for certification through this pathway. The list of states can change, so you must confirm with L&I if your state has a current agreement. The reciprocity application fee is $189.80.