Obtain Your License

Pursuing a career in the Plumbing field? Study at home for your Washington Plumbing license exam with our fully online, user-friendly, and self-paced course.

  • State Licensed Contractor Application Processing

    Washington Application Processing


    @HomePrep Application Processing is here to ensure your application to become a state licensed contractor gets filled out correctly and promptly. We provide a professional service ensuring your privacy and comfort throughout the entire process. Following your purchase of the Washington Application Processing our AP Coordinator will contact you to discuss the next steps. If you have any questions please call us at 800-952-0910. We look forward to working with you.

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  • Washington Plumbing Contractor/Journeyman – Books Only Package


    As of this time we do not offer any courses for this exam. We do offer all the required books for this exam here in one complete package. Individual books can be found in our bookstore. Please be sure to check back in the future for possible course material, as we are always adding to our course catalog.

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Requirements To Complete

About This License

To work in the plumbing trade in Washington, you must be certified by the Washington State Plumber Certification Program. Certification allows certificate holders to perform installation, alteration, or repair of portable water, liquid waste, and medical gas systems within a building in the state of Washington. The Department issues trainee, journeyman, and specialty/residential plumber certificates, as well as medical gas piping installer endorsements.

Requirements to Obtaining Your License

  • Journey Level Plumber (PL01) applicants are required to show 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.)
  • Residential (PL02) applicants are required to show 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 (PL04) applicants are required to show 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.
  • All applicants for Journeyman and Residential specialty exams are required to have completed, prior to testing, 16 hours of continuing education. With a minimum of 4 hours of that being based on electrical.

Applying For Your License

Journeyman application/exam fee is $139.10 and the Contractor Registration fee is $151. Applications can be found on Washington State Department of Labor & Industries website under Licensing & Permits.

Department of Labor and Industries
PO Box 44470
Olympia, WA 98504-4400
(360) 902-5800

Exam Details

Exams are proctored by PSI, who can be reached at (855) 746-8173. A minimum passing score of 70% is required for all exams.

The Journeyman Exam and the Residential Specialty Exam are closed book and broken down into three parts. Candidates need to pass all three portions of the exam. If they fail any portion of the exam then they will have to retake ALL portions of the exam again.

Journeyman Exam (PL01)

  • Exam One: Journey Level code and general trade knowledge, 100 questions with a time limit of 90 Minutes.
  • Exam Two: Waste and Vent Journey Level Drawings, 25 questions with a time limit of 90 Minutes.
  • Exam Three: Water Sizing Journey Level Drawings, 25 questions with a time limit of 90 Minutes.

Residential Specialty Exam (PL02)

  • Exam One: Residential code and general trade knowledge, 100 questions with a time limit of 90 minutes.
  • Exam Two: Waste and Vents Residential Drawings, 25 questions with a time limit of 90 minutes.
  • Exam Three: Water Sizing Residential Drawings. 25 questions with a time limit of 90 minutes.

Residential Service Plumber (PL04)

  • This exam is done in one portion and will have 65 questions, with a time limit of 90 minutes. Please note this exam is also closed book.


Books and References for the Exam

These books are available for purchase from our online contractor’s bookstore or by calling our office at 1-800-952-0910.

The following references are NOT allowed to be used during testing:

Exam Review Education

Please check back later for review and training for this license.

Continuing Education

All Journeyman and Residential Specialty Plumbers must obtain 16 hours of continuing education within a two-year renewal cycle. Plumber trainees must complete 8 of the required 16 hours every year. All of these required courses must be taken within the renewal cycle. We offer this online.

Reciprocity Agreement

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 case by case consideration.

How It Works


Obtain pre-approval from the state (if applicable).


Purchase Exam Prep materials.


Schedule and pass your state exams.


Submit to the state your application, licensing fee, and proof of insurance.