Licensing Guides

Washington Plumbing License: How to Become a Plumber in Washington

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Table of Contents
  1. Licensing Requirements for Plumbers in Washington

  2. Types of Plumbers Licenses in Washington

  3. Steps to Getting a Plumber’s License in Washington

  4. Benefits of Getting a Plumbers License in Washington

  5. What Is the Mean Wage for a Plumber in Washington?

  6. How Much Does It Cost to Get a Plumbers License in Washington?

  7. How to Get a Plumbers License in Washington

  8. How Long Does it Take to Get a Plumbers License in Washington?

  9. Washington Plumber Licensing Exam Details

  10. Who Issues Plumbers Licenses in Washington?

  11. Does My Washington Plumbing License Work in Any Other State?

  12. Plumbing Certifications

  13. Continuing Education

  14. Renewal

There’s no easy button you can push to speed the process of becoming a plumber. It takes time, effort, and determination, but the skills you learn can lead to a lifelong career and maybe even your own business. Almost every state in the nation requires plumbers to be licensed because it’s complicated work that affects everyone’s health and safety.

In Washington, plumbers are among the highest paid in the nation — ranked seventh according to the U.S. Bureau of Labor and Statistics. The same report says there are 482,700 plumbers nationwide and Washington employs 10,860 of them. That number is projected to grow 2% from 2022 to 2032 across the country, but in Washington the projected growth rate is more than eight times that at 17% for Plumbers, Pipefitters, and Steamfitters , according to CareerOneStop, the U.S. Department of Labor’s job search website.

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Contractors are struggling to find skilled tradesmen like plumbers, electricians, and HVACR or mechanical professionals.According to the Associated General Contractors of America 2022 AGC-Autodesk Workforce Survey, 93% of firms in the U.S. and 100% of firms in Washington had unfilled hourly craft positions,.

Licensing requirements for plumbers vary from state to state and, in some cases, from locality to locality. Washington has strict statewide standards for working in the plumbing business, beginning at the apprentice level.

Licensing Requirements for Plumbers in Washington

Is a license required for plumbers in Washington? Yes, and it is mandated from the very beginning.

The Washington State Department of Labor and Industries licenses plumbers, electricians, contractors, and several other professions. The Plumbing Certification Program certifies every level of the plumbing workforce, including trainees, journeymen, and contractors, ensuring they meet state requirements to provide safe plumbing for the public. Only state-certified plumbers can legally perform plumbing work on someone else’s property. Property owners can perform plumbing work on properties they own. Washington enacted new plumbing licensing requirements effective July 1, 2021. The changes address certified plumber shortages, expands plumber training opportunities, increases consumer protection, and provides for the creation of a new plumbing contractor license.

Types of Plumbers Licenses in Washington

What are the different types of plumbers licenses in Washington?

There are several plumbers licenses in Washington based on the scope of the work being performed, and each has its own requirements for licensure.

Plumber Trainee

Apply for a plumber trainee certificate.

Journey Level Plumber (PL01)

  • Qualified to work in all phases of plumbing construction.

  • Four years or more (at least 8,000 hours) working as a plumber trainee under the supervision of a certified journey-level plumber.

Note: Two years or more (at least 4,000 hours) must be spent working in commercial or industrial installations

  • Medical gas piping installer (MG01) is a journey level plumber who is also qualified to work on medical gas piping systems that deliver oxygen, nitrous oxide, high-pressure nitrogen, medical compressed air, medical vacuum systems, etc. Must complete at least 32 hours of training in a state-approved medical gas training course.

Residential Plumber (PL02)

  • Limited to installation, maintenance, and repair of plumbing in single-family dwellings, duplexes, and apartment buildings that do not exceed three stories.

  • Three years or more (at least 6,000 hours) working in the specialty under supervision of a certified residential or journey-level plumber.

Residential Service Plumber (PL04)

  • May service, repair, or replace existing fixtures, piping, and fittings that are outside the interior wall or above the floor in single-family dwellings and duplexes only.

  • May perform plumbing work as needed to perform drain cleaning and may perform leak repairs on any pipe, fitting, or fixture from the leak to the next serviceable connection in any residential structure.

  • Two years or more (at least 4,000 hours) working as a plumber trainee under the supervision of a journey level, residential specialty, or residential service certified plumber.

Note: First year or more (at least 2,000 hours) must be spent working under the direct supervision of a journey-level or residential specialty plumber.

Pump and Irrigation Plumber (PL03)

  • Limited to installation, maintenance, and repair of equipment that is used to acquire, treat, store, or move water suitable for drinking or irrigation purposes.

  • Two years or more (at least 4,000 hours) working in the specialty under supervision of an appropriate certified plumber (excluding PL03A and PL30).

Note: Working in this trade also requires electrical certification. See the steps to obtain a combination plumber/electrical certification.

  • Domestic well (PL03A) is limited to installation, maintenance, and repair of equipment that is used to acquire, treat, store, or move drinking or irrigation water using a pump not exceeding 100 gallons per minute or 7.5 horsepower, single phase (see for electrical requirements).

  • One year or more (at least 2,000 hours) working in the specialty under supervision of a certified plumber, (excluding PL30).

Note: Working in this trade also requires electrical certification.

Backflow Plumber (PL30)

  • Limited to maintenance and repair of existing backflow prevention assemblies within a building. It does not include installing or replacing backflow prevention assemblies.

  • An active BAT (Backflow Assembly Tester Certification) issued by the Washington State Department of Health is required.

Plumbing Contractor License

  • Corporations, Limited Partnerships, Limited Liability Partnerships, or Limited Liability Companies must first file with the Secretary of State

  • All other business structures must file a Business License Application with the Department of Business Licensing Service

  • Unless you are a sole proprietor with no employees, an Employee Identification Number from the Internal Revenue Service is required.

  • Complete the Application for Plumbing Contractor License

  • Obtain a Surety Bond or Assigned Savings Account $6,000

  • Obtain a Certificate of Liability Insurance ($250,000 combined per occurrence amount) on which the state Department of Labor and Industry must be the certificate holder. A certificate of insurance must be filed each year prior to the expiration date of the policy or the license will become automatically suspended and reinstatement fees will be assessed.

  • Pay the licensing fee.

  • Complete the Designated Plumber Assignment/Un-assignment form and submit it with the application packet.

Steps to Getting a Plumber’s License in Washington

  1. Be at least 16 years of age.

  2. Enroll in an apprenticeship program or begin working under the direct supervision of a journey-level or certified plumber.

  3. Apply for a plumber trainee certificate with the Department of Labor and Industries.

  4. Complete the hours of experience required for the discipline that you are pursuing, completing the necessary continuing education to renew your trainee certificate yearly.

  5. Apply, pay for, take, and pass the appropriate certificate of competency examination.

  6. Pay for and receive your license.

  7. Work indefinitely for a licensed contractor while keeping your license current through continuing education and renewal.    OR

  8. If you want to own your own business, you will need to register with the state as a plumbing contractor, following all the steps required including securing general liability insurance and a surety bond. 

Benefits of Getting a Plumbers License in Washington

There are many benefits to getting your Washington plumbers license:

  • Most importantly, the only legal way to work as a plumber in Washington is through licensure.

  • A trade license is proof of your experience and skill.

  • Only licensed plumbing contractors can: operate a business and advertise services, obtain commercial insurance, pull building permits and pass inspections, bid on public and government projects.

  • Having a state license protects your company and customers.

  • A license gives you a competitive advantage in the job market and increases your earning potential as you acquire more experience.

What Is the Mean Wage for a Plumber in Washington?

The annual mean wage for a plumber in Washington is $82,400 according to the U.S. Bureau of Labor Statistics as compared to the national average which is $67,840. Washington has the seventh highest annual mean wage nationally for plumbers, pipefitters, and steamfitters. As you might expect, your salary can increase as you acquire more experience, according to Indeed.com.

Apprentice: The average wage for an apprentice plumber is $23.57 per hour in Washington and $5,500 overtime per year.

Journeyman: The average wage for a journeyman plumber is $53.12 per hour in Washington and $6,750 overtime per year.

Salary can vary widely depending on the city and many other important factors, including education, certifications, additional skills, the number of years you have spent in your profession.

What Business Owners Need to Know

Getting the most out of a plumbing technician, no matter where they are in their licensing journey, takes work. ServiceTitan’s cloud-based, all-in-one plumbing software gives technicians and business owners the technology they need to do the work efficiently, and the data they need to do it smartly. 

ServiceTitan features:

  • SMS communications that keep customers informed about the technician’s visit.

  • Location-specific service history, including recorded calls, accessible from the mobile app.

  • Required forms that ensure every job is done right, driving consistency.

  • The ability to build multi-option proposals with photos, on-site, in minutes.

  • Sales presentations that make conversations with customers easier and drive average ticket.

  • Mobile payment acceptance, eliminating lost checks and increasing cash flow.

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How Much Does It Cost to Get a Plumbers License in Washington?

The cost to get started as a plumber trainee in Washington is fairly low. The fee for the plumber trainee certificate is $56.40 and that same amount yearly to renew it until your years of experience are accomplished.  Apprentice programs have different tuition costs associated with them. Some are completely covered by members and contractors, and others require trainees to pay a relatively small sum. For instance, apprentices pay $800 per year in tuition for the program offered through Local 44 out of Spokane. That’s $4,000 $227.90 – Journey Level / Residential / Residential Service

It costs $189.80 to apply to take the appropriate exam, except for the specialty plumbing Medical Gas Endorsement which is $69.80. The exam fee is $80 for three portions, which applies to both the journey-level and residential certificates, and $50 for all other exams that are a single portion. Upon successful completion of your exam, Plumber Certification will send you an invoice for the appropriate certification fee:

  • $227.90 – Journey Level / Residential / Residential Service

  • $156.70 – Medical Gas Endorsement

  • $228.00 – Domestic Pump / Pump and Irrigation

  • $157.20 – Backflow Specialty.

Plumbing contractors have the expenses of insurance, surety bond and the licensing fee is $139.10.

How to Get a Plumbers License in Washington

Becoming a plumbing professional in Washington isn’t fast, but it’s very straightforward. You must be certified by the Plumber Certification Program to work in the plumbing trade in Washington.

The plumbing trade includes all:

  • Potable water building supply and distribution pipes.

  • Plumbing fixtures and traps.

  • Drainage and vent pipes.

  • Accessories (appurtenances) within the property lines of the premises.

  • Medical gas and medical vacuum systems, and

  • Water heaters.

APPLY FOR TRAINEE CERTIFICATE: To learn the plumbing trade in Washington State and become a certified plumber, you must start as a plumber trainee. You will need to be at least 16 years old. As a trainee, you will work under the direct supervision of a certified plumber and learn through on-the-job training. You can apply online. You will need your Social Security number and a means of making an electronic payment. The Departments accepts Visa, MasterCard, Discover, and American Express credit or debit cards or electronic checks (E-Check) – a one-time withdrawal from your checking account. The fee is $56.40. You can also mail an application with a check made payable to Department of Labor and Industries to: 

Department of Labor and Industries Plumber Certification PO Box 44470 Olympia WA 98504-4470

APPRENTICESHIP/WORK EXPERIENCE: You can begin that supervised work through a formal union or non-union apprenticeship or as an entry-level employee for a licensed plumbing contractor. Plumber trainees must report their supervised work hours at least once a year by filing affidavits of experience and/or residential service affidavit of experience with the state Department of Labor and Industry. These affidavits report the qualifying, supervised hours a trainee has worked, and who their supervising plumber was. The Department put up a sample log on its website to outline the information you will need. The Department verifies all affidavits and records creditable hours as trainees work toward certification. You will need to get the required number of years and hours of experience to qualify for the state plumber examination. You also must take eight hours of approved continuing education instruction yearly to renew the trainee certificate. Each renewal costs $56.40. Trainees are encouraged to keep a log to keep track of the hours they will need to record on the affidavit of experience forms.

The required years and hours of experience are different for the different exams.

  • Residential Service — Two years or more (at least 4,000 hours) working as a plumber trainee under the supervision of a journey level, residential specialty, or residential service certified plumber. Note: The first year or more (at least 2,000 hours) must be spent working under the direct supervision of a journey-level or residential specialty plumber.

  • Residential Specialty — 6,000 hours of experience in residential or commercial plumbing.

  • Journey Level — 8,000 hours of experience. A minimum of 4,000 hours of this time must have been in the commercial plumbing trade.

  • Domestic Pump — 2,000 hours experience in this specialty.

  • Pump and Irrigation — 4,000 hours experience in this specialty.

Note: Domestic Pump or Pump and Irrigation work requires an electrical trainee card or electrical certification in that specialty. 

APPLY TO TAKE LICENSING EXAM: Once you have the required experience and education, you can apply to the Department to take the appropriate plumber exam either online or by mailing this application. The application fee for each type of certification is $189.80, except for the Medical Gas Endorsement that can be added to a Journey Plumber certification for $69.80. You will need to submit a completed application, the fee and the supporting documentation requested such as the affidavits of experience. Once approved to test, you will hear from the third-party testing agency, PSI Exams. You will then need to schedule the exam with PSI online or by phone and pay the exam fee. Journey Plumbers and Residential Plumbers will each need to take three portions of the exam, while the other specialties only require one portion. It cost $80 for three and $50 for one. More on the exam is explained below. 

PAY FOR LICENSE: After passing an examination, you will have 90 days to pay the certification fee to receive your Washington State Certificate of Competency. The certification fees are:

  • $227.90 – Journey Level / Residential / Residential Service

  • $156.70 – Medical Gas Endorsement

  • $228.00 – Domestic Pump / Pump and Irrigation

  • $157.20 – Backflow Specialty.

CONSIDER BECOMING A PLUMBING CONTRACTOR: If you want to own your own business, you will need to register with the state as a plumbing contractor. To do so, you will need to register with the Department of Revenue. You’ll also need to determine your business structure and for Corporations, Limited Partnerships, Limited Liability Partnerships, or Limited Liability Companies you will file with the Secretary of State. For all other business structures you will need to file a Business License Application with the Department of Business Licensing Service. Unless you are a sole proprietor with no employees, an Employee Identification Number from the Internal Revenue Service is required. You also must obtain a Surety Bond or Assigned Savings Account of $6,000, obtain a Certificate of Liability Insurance ($250,000 combined per property damage occurrence amount) on which the state Department of Labor and Industry must be the certificate holder. After that, you must complete and have notarized the Application for Plumbing Contractor License including the Designated Plumber Assignment/Un-assignment form and submit it with the application packet and the licensing fee of $139.10. Once approved, you will be a registered plumbing contractor.

How Long Does it Take to Get a Plumbers License in Washington?

The amount of time it takes to become a plumber in Washington depends upon the type of license you are seeking. As stated above to qualify to test for the Journey Level Plumber certification will take at least 8,000 hours of work experience or roughly four years. Most apprenticeships for the level of licensure are five years long. The amount decreases from there depending on the scope of work you want to be permitted to do. The Residential Plumber certification takes at least 6,000 hours or about three years. Residential Service and Pump Irrigation take 4,000 hours or about two years and Domestic Pump requires the fewest at 2,000 hours for this specialty.

Washington Plumber Training programs and schools

Since the state of Washington requires plumbing professionals to begin their career journey as a certified trainee, you may not choose to get a post-secondary degree. However, if you want to build your knowledge base before beginning as a trainee there are programs intended to prepare you to get started in the plumbing industry.

The Plumbing Technician Program at Perry Technical Institute in Yakima is a one-year program that teaches students about safety, fittings, power tools, drains, backflow, venting, and water distribution systems, plumbing fundamentals, math and blueprint reading. It includes the installation of piping, fixtures, valves, water heaters, and professional development for the plumbing industry. The Uniform Plumbing Code (UPC) is used and applied throughout the program. The total tuition and fees for this program are estimated at $20,421.

Apprenticeship: The primary training path in Washington is through apprenticeship. There are several formal apprenticeship opportunities. Local United Association union chapters are considered the gold standard in apprenticeships in the trades. The UA Chapters are listed here. Each has a slightly different way of doing things. You will want to apply to the local chapter where you live. Local 598 in Pasco offers a Plumbers and Steamfitters Apprenticeship that is a five-year program consisting of 2,000 hours of on-the-job training and 250 hours of classroom instruction each year for five consecutive years. Apprentices have the same curriculum for the first and second year and then move to a specialized training track to become a Steamfitter, Plumber, Pipe Welder or HVAC-R Technician. UA Local 32 in Seattle offers apprenticeships through the Joint Apprenticeships Training Center in Renton. Here are the details of how to apply.

There are many other ways to find an apprenticeship. The Washington State Department of Labor & Industries offers a tool on its website to help apprentices find openings and help employers find apprentices. The (ARTS) Apprenticeship Registration & Tracking system helps both. There’s also advice for “Getting Started” and “Apprenticeship Preparation” offered through the Washington State Apprentice and Training Council (WSATC).

Employers in Washington are mandated by law to follow an apprentice model — pairing new employees with others who are licensed to begin hands-on training. They are often willing to offer a registered apprenticeship with  the U.S. Department of Labor if you ask. That will give you credentials that will go with you anywhere. 

One other resource is an organization called Career Connect Washington. It is a “consortium of business, education, labor and government leaders who are committed to ensuring that every young adult in Washington will have multiple pathways to self-sufficiency and fulfillment, strengthened by a comprehensive statewide system for career connected learning” because the vast majority of today’s jobs require some training after high school. Some of the programs offered through Career Connect Washington may help you.

Tuition: Apprenticeships usually have some up-front costs for books or tools and sometimes a tuition fee as well, but the apprentice will be paid a percentage of the journeyman rate and will receive periodic wage increases as they meet program requirements. The cost of tuition at a vocational school or college can range from a few thousand dollars for an online program or at a community college to $50,000 per year at a state or private school.

Program Prerequisites: You must be at least 18 years old and have a high school diploma or a GED and demonstrate mastery of basic high school level math. You may also need a driver’s license, a clean bill of health, and to pass a drug test.

On-the-Job Experience: While on the job you will need good customer service skills, be detail-oriented, have some mechanical capability, and be physically fit because the job can include some heavy lifting and hours of walking, standing and working in tight spaces. 

Washington Plumber Licensing Exam Details

The state of Washington has contracted with PSI Exams, a third-party testing service, to conduct all of its licensing examinations. Each of the plumbing certification exams is explained in this Candidate Information Bulletin. Most of the exams are closed book. The only open book exams are the Medical Gas and Pump and Irrigation examinations. All of them have a time limit of 90 minutes to complete and require at least a 70% to pass.

Journey Level Plumber (PL01) comprises three portions.

  • Journey Level code and general trade knowledge: 100 questions

  • Waste and Vent Journey Level Drawings: 25 questions

  • Water Sizing Journey Level Drawings: 25 questions

Residential Plumber (PL02) comprises three portions.

  • Residential code and general trade knowledge: 100 questions

  • Waste and Vent Journey Level Drawings: 25 questions

  • Water Sizing Journey Level Drawings: 25 questions

  • Medical gas piping installer (MG01): 100 questions

  • Residential Service Plumber (PL04): 85 questions

  • Backflow Plumber (PL30): 55 questions

  • Pump and Irrigation Plumber (PL03): 45 questions

The fee for three portions is $80 and $50 for one portion. The Bulletin also specifies which reference materials you may use for the two open book exams and what items are not allowed in the testing center. There are 15 PSI testing centers in Washington: in Arlington, Bremerton, Ellensburg, Everett, Kennewick, Lakewood, Liberty Lake, Olympia, Puyallup, Seattle (Bellevue), Snohomish, Spokane, Tacoma, Vancouver, and Yakima.

Who Issues Plumbers Licenses in Washington?

The Washington State Department of Labor and Industries certifies all plumbing professionals in the state and issues plumbing contractor licenses as well. You must be certified by the Washington State Plumber Certification Program to legally work in the plumbing trade in Washington. The penalties for performing, bidding, and advertising plumbing work without proper certification and licensing range from $500 to $5,000 for each infraction.

Does My Washington Plumbing License Work in Any Other State?

Every state has different licensing requirements. Minimum work experience thresholds will vary, and many will require that you document that experience and pass a licensing exam. Be sure to check those mandates before beginning plumbing work in another state, even if you’ve been certified in Washington.

Washington has reciprocal certification with Idaho for journey-level plumbers. All other out-of-state plumbers can present a comparable license from another state or show equivalent experience in the U.S. military for consideration.

One more note, there is an Apprenticeship Reciprocal Agreement between Washington, Oregon, and Montana. The intent is to provide freedom of movement of the registered apprenticeship workforce in the three states. Under the agreement it is understood that when an apprentice registration occurs in any one of the three states, duplicate registration is not required in the others for apprentices to be eligible to work there. 

Plumbing Certifications

Other certifications can help you demonstrate your proficiency to potential employers and clients. National Inspection Testing and Certification (NITC),  International Association of Plumbing and Mechanical Officials (ASSE Certifications) and other professional certifications are not required but may make you a more attractive hire to prospective employers or can increase your marketability to customers.

Continuing Education

You must complete continuing education in Washington before being permitted to renew your certification at every level. The Department posts lists of approved providers for plumber certification and for the pumping industry.

Plumber Trainees are required during a two-year period to complete at least 16 hours of continuing education — eight hours of plumbing code and at least four hours of electrical trade related classes from the currently adopted Washington state plumbing and electrical codes. The remaining four hours may be plumbing or electrical trade related classes. You must complete at least eight hours of continuing education every year to renew your certificate. For example, if you take eight hours of Code one year, the following year you must take a minimum of four hours of Industry-Related Electrical (IRE), and another four hours in Code, IRE, or Industry-Related Plumbing (IRP).

Journey Level, Residential, and Residential Service Plumbers must complete 24 hours of continuing education within the three year certification period — a minimum of 12 hours of Uniform Plumbing Code (CODE), plus a minimum of four hours of IRE. The remaining eight hours can be in any Code, IRE, or IRP area.

Renewal

Your plumber certification renews on your birthdate every three years for journey level, residential, residential service, backflow, and domestic pump and pump and irrigation plumbers.

To renew your plumber or reciprocal certification online, you will need:

  • Your 12-digit certification (license) number.

  • Your Social Security number.

  • An active journey level or specialty plumber certification (not suspended or canceled).

  • Proof of your continuing education on file with L&I from your course provider.

    • Note: If you do not complete your continuing education by your expiration date, late fees will apply and you will be unable to renew online.

  • An electronic payment: Visa, MasterCard, Discover, and American Express credit or debit cards are accepted. The state also accepts electronic checks (E-Check) – a one-time withdrawal from your checking account.

  • Required Fees

    • $227.90 – Journey level, residential specialty, & residential service plumber certification renewal.

    • $156.70 – Medical gas endorsement specialty plumber renewal.

    • $228.00 – Domestic pump or pump and irrigation specialty plumber renewal.

    • $157.20 – Backflow assembly tester renewal.

Note: You cannot renew online if you have any outstanding, unpaid plumbing infractions, or your certificate is suspended.

To renew your existing plumber certification by mail, print the Plumber, Medical Gas, or Trainee Renewal form and follow the instructions on the form.

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