Plumbing Licensing Requirements

In 2020, the Legislature passed significant changes to plumbing laws (SB 6170). This page highlights a few of the changes, including the creation of a new plumbing contractor license. Plumbing and related industries worked together to propose the changes to address certified plumber shortages, expand plumber training opportunities, and increase consumer protection.

Plumbing Contractors

Beginning July 1, 2021, the “specialty plumbing” registration was no longer valid, and general contractors could no longer perform work with a certified plumber. All plumbing contract work must be performed by a new Licensed Plumbing Contractor under Chapter 18.106 RCW.

  • Licensed plumbing contractors can choose to also be registered as general contractors under Chapter 18.27 RCW, to perform non-plumbing works such as installing cabinets, tile, etc.
  • Plumbing contractors must designate to L&I, a certified plumber as the “dedicated plumber” for their company. This could be an owner/partner or a full-time employee.

Phase 2 rules are being finalized to implement the changes to Chapter 18.106 RCW, which took effect July 1, 2021. Learn more about the rules. Additional phase 3 rule making will begin soon focused on some outstanding items and the phase out of the construction contractor plumbing specialty.

General Contractors

As of July 1, 2021, general contractors cannot offer, advertise, and/or bid on projects that require plumbing work. 

  • General contractors can choose to also be licensed as plumbing contractors under Chapter 18.106 RCW to perform contract plumbing work.

Check back often for updates, or stay informed about the new requirements by signing up for our email distribution list below. Review the new licensing requirements FAQs.

How to Apply

To register with L&I as a Plumbing Contractor, you must:

The order you complete these steps can affect how quickly you can complete the registration process.

Getting started

For the fastest and simplest registration process, we recommend this three-step process:

Step 1: Decide on your business structure and name

  • If you are setting up a sole proprietor or partnership, decide on your business name, or if you already have registered your business and have a Uniform Business Identifier (UBI), proceed to step 2.
  • If you are starting a business that is incorporated, such as an LLC or Corporation, you should contact the Secretary of State or a private attorney to incorporate your business.

If you are unsure which business structure you should use, see our guide, Applying for Your Washington Business License: A Step-by-Step Guide (F101-079-000), or visit for in-depth information on starting and structuring your business.

Step 2: Purchase your surety bond and insurance

To register as a contractor, you will need to purchase:

  • A Washington Continuous Plumbing Contractor Surety Bond in the amount of $6,000
  • A general liability insurance policy in the amount of:
    • $200,000 in public liability and $50,000 property damage, or
    • $250,000 combined single limit

Your bond and insurance must use your exact business name, and L&I must be listed as a certificate holder for your liability insurance. If you are unsure how to purchase your surety bond and insurance, contact a licensed insurance agent.

Step 3: Visit your local L&I office

At your local L&I office, our customer service representatives can help you register your business and complete your application. To avoid unnecessary delays, you will need to have the following:

  1. The business name and business structure you have chosen, or your business registration and UBI number from the Department of Revenue.
  2. An original, completed Application for Plumbing Contractor License (F627-051-000) with notarized signatures, or we can help you complete your application and notarize signatures with any applicants who are present.
  3. Your continuous contractor surety bond or assignment of savings.
  4. Your certificate of general liability insurance.
  5. Your application fee.
  6. An original, completed Designated Plumber Assignment (F627-052-000) with notarized signatures, or we can help you complete your application and notarize signatures with any applicants who are present.
  7. Your designated plumber fee.

Additional ways to apply

You can mail your completed, signed, and notarized Application for Plumbing Contractor License (F627-051-000) to the address below along with:

  • Continuous Plumbing Contractor Surety Bond or assignment of savings.
  • Certificate of general liability insurance.
  • Designated Plumber Assignment.
  • A check or money order payable to the Department of Labor & Industries.

Mail to:

Plumbing Certification
P.O. BOX 44470
Olympia, WA 98504-4470

Note: All signatures on your application must be original and notarized. We cannot accept a copy of your application.

Completed applications submitted by mail are currently taking 1-2 weeks after receipt to process and activate your registration. Once your business is licensed, it will be listed in our Verify a Contractor, Tradesperson, or Business tool. You will receive a license card in about 2 weeks.

If any of the required information is missing or incorrect, we will contact you to help complete your application.


If your business has not had any changes, such as changing partners, a business name or structure change, or changing your specialty, you can renew using one of the options below. If you need to make changes or update your business information, see the instructions below.

Before you complete your renewal, use our Verify a Contractor, Tradesperson, or Business tool to make sure that your:

  • Surety bond or assignment of account and general liability insurance information is up to date.
  • Plumbing Contractor license is not suspended.

Renew online

To renew online, you will need the following information:

  • Your 12-digit Contractor Registration number.
  • Your UBI number.
  • The required fee of $139.10.
    • We accept Visa, MasterCard, Discover and American Express credit or debit cards. We also accept E-Check, a one-time withdrawal from your checking account.

Renew by mail

Review the information on the plumbing contractor license renewal card you received in the mail. If your information is correct, and your required documentation is current, mail the renewal card with a check or money order in the amount of $139.10 to:

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

Renew in person

Bring your renewal card to your nearest local L&I office. You can pay by cash, check, money order, or credit/debit card.

Change/Update Your Insurance or Bond

If you have a new bonding company/bond amount or a new insurance company or coverage amount since you last renewed, you will need to update your information before you renew.

New or updated bond

To renew your registration, we must have:

  • Your new surety bond, signed by your bonding agent with the bonding company’s seal.
    • The bond must be the original, uncorrected document, not a photocopy.
    • The name of your business on your bond must be exactly the same as the one on file with L&I.
    • It must reach L&I before the “filing date” shown on the bond.

New or updated insurance

To renew your insurance, we must have:

  • Your new certificate of general liability insurance, for at least $250,000.
  • An electronic confirmation sent to L&I directly from your insurance agent, or an original, uncorrected paper certificate of insurance signed by your insurance agent (not a photocopy). The name of your business on the certificate must be exactly the same as the one on file with L&I.

Bring all required documents and your renewal payment of $139.10 to your local L&I office, or mail it to:

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

Note: Include your registration renewal card with your paperwork. This will help us quickly process your renewal.


We suspend a license when the registration requirements are not met, such as a bond or insurance cancelling or expiring or an unsatisfied judgment.

When we suspend a license, we will notify you by both certified and first-class mail within 2 days of the suspension. The letter will tell you what you need to do to reinstate your license.

You may reinstate your license online or in person. To reinstate, you must:

  • Provide your 12 character Plumbing Contractor License Number, email address, and phone number.
  • Provide proof that you corrected the issue, such as a new bond or insurance certificate or satisfaction of judgment.
  • Pay the reinstatement fee of $69.50.

Reinstate online

By reinstating online, your registration will show as active as soon as you make your payment.

Reinstate in person or by mail

You may bring the required documents and payment to your local L&I office. We accept cash, checks, money orders and credit/debit cards.

You may also mail the required documents and payment (check or money order) to:

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