How to Hire a Licensed Plumber in Toronto (Checklist + Red Flags)
By Serhiy Marunchuk, Master Plumber · Licence T95-4969603 · Updated August 17, 2026
Hiring a plumber in Toronto comes down to four checks: a valid Ontario Certificate of Qualification, a current City of Toronto contractor licence, real liability insurance plus WSIB coverage, and a written quote with scope and warranty. This guide gives you the exact questions to ask and the red flags that should end the conversation.
Published June 15, 2026 · Last updated August 17, 2026

Introduction
Plumbing is a compulsory trade in Ontario, which means the person doing the work is legally required to hold a Certificate of Qualification — and yet plenty of unlicensed operators still take Toronto jobs, especially for emergency and basement work where homeowners are under pressure. Hiring the right plumber is not about finding the lowest number; it is about verifying four things before any money changes hands: trade qualification, City of Toronto contractor licensing, insurance and WSIB coverage, and a written quote you can actually hold someone to. This guide walks through each check, the questions that flush out a pro from a price, and the red flags that should end the call. For an idea of what fair pricing looks like once you have a qualified shortlist, pair it with our Plumbing Cost Guide Toronto 2026. Licensing matters most on permit-and-rebate work like backwater valve installation and on high-pressure emergency calls — exactly where unlicensed operators concentrate.
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June 2020“I can’t recommend Tornado plumbing enough. Sergei and his team are literally the best. Sergei always provides the best recommendations and gives you his honest opinion. He doesn’t over sell and gives you the best advice. I had to have my main valve change which was something we had discussed a while ago from another service I had hired him for. The shut off valve was old and had lead component. I knew from past experience that anytime I needed to turn it on or off, it would start leaking. There was also a lead pipe leading underground. I made the decision to change all the lead pipe as opposed to just changing the shut off valve because it would eventually need to be changed regardless. Sergei dug from the front of my house to the water valve in my basement with minimal interruptions to my tenants, and minimal mess. This speaks to his attention to detail. He goes over and beyond my expectations. Thank you Sergei and Tornado Plumbing.”
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May 2025“I highly recommend Serhiy. I have used him several times, and he always does quality work. He recently replaced a toilet, faucet, and house shut-off valve, all of which had leaks and were faulty. He knows what he is doing - He is licensed, experienced, efficient, and pays attention to details. His pricing is very fair, and unlike some others, the price doesn't go up based on the area you live in. All this is hard to find in professionals. Someone honest (he won't fix things that don't need repair to create work) and who takes pride in a job well done. I will definitely call him again for future plumbing needs.”
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August 2022“Tornado Plumbing and Drains did an excellent job replacing my old drains and correcting some very old plumbing in my old house in only 2 days. Peter was very thorough in evaluating and explaining in detail the problems with the drains and how they would be repaired. He was extremely patient in answering all of my concerns. The team showed up on time, protected the work areas and did an excellent job with the final clean-up. They are assisting me with the rebate for the valve also. The cost for the work was very reasonable and several thousand dollars less than two other companies. I have already recommended Tornado to several friends and recommend them without reservation.”
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Master plumber T95-4969603 · Plumbing contractor T94-4992639 · Drain contractor T87-4722944 · Building renovator T85-4728632 · Plumbing license FI6216638.
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$5M general liability, WSIB cleared. Same-day and after-hours dispatch across Toronto, Etobicoke, North York, Scarborough, York, Mississauga, and Burlington.
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Every job Tornado Plumbing & Drains completes in Toronto and the GTA — repair, install, replacement, drain work, sewer work, fixture work — is backed by a 25-year workmanship warranty. The written terms are provided with every quote. A real warranty is one of the clearest signals you are dealing with a licensed shop rather than a cash operator: if our work fails within 25 years of the install date, we come back and make it right.
Quick answer
Before you hire any plumber in Toronto, confirm four things: (1) an Ontario Certificate of Qualification for the Plumber (306A) trade — plumbing is compulsory, so the tradesperson must hold one; (2) a current City of Toronto plumbing/drain contractor licence for the company doing the work; (3) commercial general liability insurance and a WSIB clearance certificate; (4) a written, itemized quote that states scope, materials, permit responsibility, and warranty. If a quote is verbal-only, cash-only, demands a large upfront deposit, or the contractor cannot produce licence and insurance numbers, walk away. A plumbing inspection from a licensed shop is the safest way to get an accurate scope before committing.
How do I verify a plumber is licensed in Toronto before hiring?
Verify four things first: an Ontario Certificate of Qualification for the Plumber (306A) compulsory trade, a current City of Toronto plumbing/drain contractor licence, commercial general liability insurance ($2M-$5M) plus a WSIB clearance certificate, and a written itemized quote. Walk away from cash-only, verbal-only, or large upfront deposit requests.
The four things to verify before you hire
Trade qualification: in Ontario, Plumber is a compulsory trade regulated by Skilled Trades Ontario. The tradesperson must hold a valid Certificate of Qualification (or be a registered apprentice working under a licensed journeyperson).
City licence: Toronto requires plumbing and drain work to be performed by a licensed contractor. Ask for the company's contractor licence number and the master plumber's licence behind it.
Insurance: ask for proof of commercial general liability (look for coverage in the $2M–$5M range) and a current WSIB clearance certificate so you are not liable if a worker is injured on your property.
Permits: most fixture swaps do not need a permit, but new rough-in, water service, sewer, and backwater valve work usually do. A licensed plumber pulls the permit; an unlicensed one asks you to.
Written quote: scope, materials, labour, permit responsibility, and warranty in writing. Verbal-only quotes are the single most common source of plumbing disputes.
Reviews and references: cross-check Google and HomeStars, and confirm the business has a physical address and a real phone line — not just a lead-gen landing page.
When a quick verify is enough vs full due diligence
A quick verify is enough for
Small, low-risk fixture work — a faucet swap, a toilet fill valve, a single shut-off — where the job is an hour or two and no permit is involved. Confirm the plumber is licensed and insured, get the price in writing, and proceed.
Do full due diligence when
The job involves rough-in, repiping, water service, sewer, backwater valve, or anything behind a wall or under a slab. These are permit-and-inspection jobs where unlicensed work can fail inspection, void insurance, and cost far more to redo than to do right the first time.
What full due diligence looks like
Get the contractor licence number, the master plumber's licence number, a WSIB clearance certificate, and a certificate of insurance naming the coverage limits. Confirm who pulls the permit, get an itemized written quote with a warranty term, and check that the company has a verifiable track record. For larger jobs, a documented plumbing inspection up front prevents the mid-job change orders that inflate the final bill.
Why hiring carefully matters more in Toronto
Toronto's housing stock skews old, and that changes the stakes of who you hire. Century homes in the central, east, and west neighbourhoods often have galvanized supply, lead service lines, and clay or cast-iron drains that an inexperienced plumber can damage or misdiagnose. Combined sewers in those same areas mean backwater valve and basement work is permit-and-inspection territory, and the City's Basement Flooding Protection Subsidy only reimburses work done by a licensed contractor with proper documentation. Hire an unlicensed operator and you risk failed inspections, a denied rebate, voided home insurance after a future claim, and no recourse when the work fails — because there is no licence to complain against. A licensed Toronto plumber pulls the right permits, knows the local code, and documents the job so your warranty and any City rebate actually hold up.
Where to go next
Get a documented scope and condition report before you commit to a major job — the safest way to compare quotes on equal footing.
The full category of licensed repair and installation services across Toronto and the GTA.
Behind-the-wall work where licensing, permits, and warranty matter most.
New rough-in is permit-and-inspection work — exactly the kind of job to hire a licensed contractor for.
Sources cited in this guide
Ready to hire the right way
Start with a documented Plumbing Inspection & Maintenance visit so you know the real scope, then compare quotes on equal terms. Browse the full Plumbing Repairs & Installations category for licensed service across Toronto and the GTA. Calls go through 647-784-8448.
Common questions
How do I check if a plumber is licensed in Ontario?
Plumbing is a compulsory trade in Ontario, so the tradesperson must hold a valid Certificate of Qualification for the Plumber trade, issued through Skilled Trades Ontario. Ask for the qualification and the company's City of Toronto contractor licence number, then verify them. A licensed pro will give you those numbers without hesitation.
Does a plumber in Toronto need a permit for my job?
Most simple fixture swaps — a faucet, a toilet, a shut-off — do not require a permit. New rough-in, repiping, water service, sewer, and backwater valve work usually do. A licensed plumber pulls the permit and books the inspection as part of the job. If a contractor asks you to pull the permit yourself, treat it as a red flag.
What are the biggest red flags when hiring a plumber?
Cash-only with no receipt, a large upfront deposit before any work, a verbal-only quote, no proof of licence or insurance, pressure to decide on the spot, and no written warranty. Any one of these is reason to pause; two or more is reason to walk away.
Why hire a licensed plumber instead of a handyman?
Licensed work passes inspection, keeps your home insurance valid, and is eligible for City rebates like the Basement Flooding Protection Subsidy. It also comes with recourse — a licensing body and a warranty stand behind it. Unlicensed work can fail inspection, void coverage, and leave you with no one accountable when it fails.
Are you licensed and insured in Toronto?
Yes — Master plumber T95-4969603, Plumbing contractor T94-4992639, Drain contractor T87-4722944, Building renovator T85-4728632, Plumbing license FI6216638, with $5M general liability and WSIB cleared. Tornado has been serving Toronto and the GTA since 2015 with over 1,200 completed jobs, backed by a 25-year workmanship warranty.
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