Quick answer
In Washington, plumbing work on someone else's property must be done by an L&I-certified plumber working through a licensed plumbing contractor. Before hiring, use L&I's free Verify tool to check the company's license, bond and workers' comp status and the individual plumber's certification. Then get a written estimate, ask about permits, and be wary of pressure, cash-only demands or large deposits.
What Washington requires of plumbers
The Washington State Department of Labor and Industries (L&I) says only L&I-certified plumbers can legally perform plumbing work on someone else's property. Property owners may do plumbing work on property they own. L&I certifies plumbers after confirming they have completed required training hours and passed the exam.
Businesses have a separate requirement. L&I says that since July 1, 2021, all plumbing contract work must be performed by a licensed plumbing contractor under chapter 18.106 RCW. The old specialty plumbing registration is no longer valid, and general contractors can no longer offer, advertise or bid on projects that require plumbing work.
Each plumbing contractor must name a certified plumber to L&I as its designated plumber. That person can be an owner, a partner or a full-time employee. This matters for you: a company's license alone does not tell you whether the person who shows up at your door is certified.
How to verify a plumber with L&I
L&I's Verify tool is free and covers both the business and the individual. L&I says you can search by L&I account ID or contractor license number, by UBI (business license) number, or by full or partial business or owner name. Ask any plumber for their company name and license number up front. A company that is licensed will have no trouble providing it.
On L&I's contractor verification page, the things to confirm are an active contractor license, an active and paid-to-date workers' comp account if the company has employees, any lawsuits against the contractor's bond, and any safety or construction citations. For plumbing work, L&I also says to confirm that the individual tradesperson is certified in Washington. Check the owner names too, so you know who is behind the business.
Two cautions apply. L&I updates its database on weekdays by 5 a.m. Pacific and states that it does not guarantee the information is accurate or current, so recheck anything important. L&I also says it will never call and ask you to pay licensing or registration fees over the phone.
- Search the business by name or license number and confirm the license is active.
- Look up the individual plumber and confirm current certification.
- Check for bond lawsuits, safety citations and other infractions.
- If the company has employees, confirm its workers' comp account is active.
- Compare the name on the lookup with the name on the truck, the estimate and the invoice.
Bond and insurance: what to look for
L&I says a plumbing contractor needs a continuous surety bond of $6,000 (or an assignment of savings) and general liability insurance of either $200,000 public liability and $50,000 property damage, or $250,000 combined single limit. The bond and insurance must use the exact business name, and L&I must be listed as a certificate holder. These figures come from L&I's page at the time of writing, so confirm them there before you rely on them.
Sources describe the lookup slightly differently. L&I's page describes checking for lawsuits against a contractor's bond. A local plumbing company's guide describes confirming in the same tool that the bond is current. If the lookup does not show what you need, ask L&I, or ask the plumber for proof of coverage.
A $6,000 bond is a limited backstop, not a guarantee that a large problem will be covered. For larger projects, L&I suggests considering a performance bond, and its contractor guide suggests asking to see the contractor's liability policy. Workers' comp rules differ for owner-operators: L&I's Hire Smart guide says sole proprietors without employees are not required to have a workers' comp account.
Permits and inspections
L&I's Hire Smart guide says permits and inspections confirm that work meets applicable codes, including plumbing codes. Building and plumbing permits are issued by your county or city, not by L&I's plumber certification program. The contractor is normally responsible for obtaining permits, and L&I lists a contractor who asks you to pull the permit yourself as a warning sign.
Which repairs need a permit differs by city and county, and the L&I pages reviewed here do not give a statewide list, so ask your local building department. Ask the plumber whether your job needs a permit, whether permit fees are in the estimate, and who schedules inspections. L&I says to make sure inspections happen before work is covered, because uncovering hidden work later costs extra time and money. Keep copies of permits and inspection confirmations.
Written estimates, contracts and payment
L&I and the Washington Attorney General's office both advise getting at least three bids, in writing. L&I says to compare scope of work, warranties, references, completion dates and price, and warns that focusing only on price can produce poor results. The Attorney General's consumer protection advice is to never sign for work on the same day you first meet a company.
L&I says a written contract should include the price including sales tax, payment terms and completion date, permit fees if applicable, the specific work, a list of materials, major suppliers and subcontractors, and warranties and the change-order process. It also says you should receive the legally required Disclosure Statement Notice to Customers before work begins. That guidance is aimed at construction projects in general, so smaller repairs may be simpler. Even then, get the scope and price in writing before work starts.
On payment, L&I suggests a reasonable down payment, paying in phases tied to completed work, holding back part of the payment until you are satisfied, and avoiding full payment before work is complete and inspected. Get a receipt for every payment, and get any change in scope in writing.
Emergencies strain all of this, since three bids may not be realistic with water on the floor. The practical compromise is to shut off the water, get a written scope and price for stopping the damage, and save larger decisions for when the immediate problem is under control. On cancellation, the Attorney General's office says Washington gives three business days to cancel certain door-to-door sales, but the federal rule says the right to cancel does not apply if the work is needed because of an emergency. Do not count on being able to cancel.
Red flags, especially in an emergency
L&I's list of scam warning signs, plus advice from the Attorney General's office, covers most of what to watch for.
After-hours work needs context. L&I flags contractors who want to do most of the work on weekends or after hours, but plumbing emergencies do not follow business hours. After-hours availability by itself is not a red flag. The concern is a contractor whose pricing, pressure or paperwork also looks wrong.
- Credentials or references that cannot be verified
- Special prices that expire if you sign today, or other high-pressure tactics
- Cash-only payment, large deposits, or full payment up front
- Payment requested to an individual rather than the business
- No written contract or incomplete estimate
- A request that you pull the permit yourself
- Unusually long warranties or offers that seem too good to be true
- A long list of extra repairs beyond the problem you called about. The Attorney General's office describes a case where a clogged sink call turned into thousands of dollars of unnecessary work.
Questions to ask before you hire
These questions follow from the L&I and Attorney General guidance above. A good plumber will answer them plainly.
- What is your company name and L&I license number, and who is your designated plumber?
- Is the person coming to my home a certified plumber, and what is their certification?
- Can I have the estimate in writing, with the scope, price, materials and warranty?
- Does this job need a permit, who will obtain it, and is the fee included?
- How and when do you expect to be paid, and what is the deposit, if any?
- What happens if you find additional problems once work begins? How will changes be approved?
- Do you carry liability insurance, and can you show proof?
When to call Pyper Plumbing
If you have a plumbing emergency such as a leak, a failed water heater, a burst pipe or a sewer backup, shut off the water if it is safe and call a plumber you have checked. Pyper Plumbing provides emergency repair, leak detection and repair, water heaters, drain cleaning, sewer line repair, toilets, faucets, fixtures, garbage disposals, repiping and frozen pipe repair in Snohomish, Skagit, Whatcom and Island counties.
Run the same checks on us that you would on anyone else. Use L&I's Verify tool, ask for the estimate in writing, and ask the questions above.
Common questions
How do I check if a plumber is licensed in Washington?
Use L&I's free Verify tool. Search by business name, owner name, UBI number or license number to confirm the contractor license, then check the individual plumber's certification and any citations or bond lawsuits.
Does a plumber need a permit to work on my home?
It depends on the job and your city or county. L&I says plumbing permits come from your county or city, and the contractor is normally responsible for them. Ask your local building department which repairs need one.
Can I cancel a plumbing contract after signing?
Not always. The Attorney General's office describes a three business day cancellation right for certain door-to-door sales, but the federal rule excludes work needed because of an emergency. Read the contract before you sign.
Is it a red flag if a plumber only comes after hours?
Not by itself in an emergency. L&I flags contractors who want to do most work after hours, but the stronger warning signs are pressure, cash-only demands, large deposits and no written estimate.
Sources
Facts in this guide come from the following references. Local rules and manufacturer instructions can differ, so follow your utility and your equipment manual.
- Washington L&I: Verify a contractor, tradesperson or business
- Washington L&I: Plumbing licensing requirements (plumber certification)
- Washington L&I: Plumbing contractor licensing requirements
- Washington L&I: Plumbing program
- Washington L&I: Hiring a contractor
- Washington L&I: Hire Smart step by step
- Washington L&I: Hiring a contractor, remodeler or handyman (F625-084-000)
- Washington Attorney General: Cancellation rights
- Washington Attorney General: Never commit to big home repair jobs the same day
- Absolute Plumbing: How to verify a plumbing contractor's license in Washington
This guide is general information, not a substitute for an on-site inspection. If you smell natural gas, leave the building and call 911 or your gas utility. Pyper does not perform gas line work.
