How to hire a plumber in Ontario

To hire a plumber in Ontario, read their reviews and look at past work, check the person doing the work on the Skilled Trades Ontario public register, get two or three written quotes for the same job, ask about insurance and permits, and make sure the written estimate is part of your contract. Plumbing is a compulsory trade in Ontario, so the person doing the work must be certified or a registered apprentice. In Toronto, the business also needs a City plumbing contractor licence.

1. Shortlist and read the reviews

Start with plumbers who list your kind of job (a water heater, a drain, a backwater valve), work in your town, and answer emergencies if you need that.

When you read reviews:

• Look for recent, specific reviews that name the job, the price range and how the problem was solved. "Great service" tells you little.
• Read the low ratings. A fair answer from the business to a complaint is a good sign. Look for repeated problems: no-shows, surprise charges, work that had to be redone.
• Weigh the count and the dates. A handful of recent reviews says more than many from years ago.
• On Zulma Atlas, each plumber's page shows the services they publish and the towns they serve, and has reviews from homeowners. A review tied to a job booked through Zulma is marked "Verified booking". A business that has claimed its page can answer reviews, and can show a verified licence where its trade is licensed.

2. Look at their past work

• Ask for photos of a similar job they've done. A plumber who installs water heaters every week will have them.
• Ask for a reference from a job like yours in the last year, and call them: was it on time, on budget, and clean?
• For a bigger job (a basement bathroom, repiping, a backwater valve), ask how many they did last year and whether they pulled the permits.
• Some Atlas pages show the business's own photos and videos; where they don't, ask.

3. Check the licence

Plumbing (Plumber 306A) is a compulsory trade in Ontario. To do plumbing work legally, a person needs:

• a Certificate of Qualification, or
• a Provisional Certificate of Qualification, or
• a Registered Training Agreement, meaning they're an apprentice working under the rules.

Their details must appear on the Skilled Trades Ontario Public Register, and homeowners can use it to check the people they hire. Search the name of the person who will do the work, not just the company. A Certificate of Qualification has to be renewed every year, and the register shows when it expires.

iSources: Government of Ontario, "Compulsory trades and enforcement" (updated 9 October 2026); Skilled Trades Ontario, "Plumber".

In Toronto, any business that installs or repairs plumbing, or advertises as a plumbing contractor, must also hold a City of Toronto Plumbing Contractor licence. Toronto's basement flooding subsidy only pays for work done by a contractor with a City business licence.

iSource: City of Toronto, "Plumbing Contractor" (modified 3 June 2026).

4. Ask the right questions

• Who will do the work, and are they on the Skilled Trades Ontario register?
• Do you carry liability insurance? Can I see proof?
• Is this a flat price or hourly? What's the minimum charge, and is there a diagnostic fee?
• What's included: parts, labour, disposal, cleanup?
• Does this job need a permit? Will you pull it and book the inspection?
• What warranty do you give on parts and labour?
• When can you start, and how long will it take?

5. Compare quotes on the same job

• Ask each plumber to quote the same scope, in writing.
• Compare the total, including HST, not only the hourly rate.
• A quote far below the others can leave out parts, permits or cleanup. Ask what's missing.
• For typical rates and job prices, see our guide to plumber rates in Ontario. Most charge $115 to $160 an hour, and more in the GTA.

6. Permits

In Toronto, repairing or replacing a plumbing fixture usually needs no permit. Installing or changing plumbing, adding a backwater valve or a backflow preventer, or finishing a basement with new plumbing does need one. A standalone plumbing permit there costs $23.20 per fixture for a house (2026). Other cities set their own rules, so ask your plumber or your city's building department.

iSource: City of Toronto, "When Do I Need a Building Permit?" (modified 21 July 2026) and "Stand-alone Plumbing & Drain Permits".

7. Your rights on price and contracts

• Any home renovation or repair contract worth more than $50 must be in writing.
• If a written estimate is part of the contract, the final price can't be more than 10% over it unless you agree to new work or a new price.
• Keep the deposit to no more than 10%, and never pay the full amount before the work is done.
• If you sign at home, you have 10 days to cancel for any reason.

iSource: Government of Ontario, "Your rights when starting home renovations or repairs" (updated 6 August 2026).

8. After you hire: keep track of the job

• Before work starts: photograph the area, and keep the signed contract and the estimate.
• During the job: if the plan changes, get the new price in writing before the extra work. Note the permit number and the inspection date.
• At the end: check the work with the plumber, run the taps, and look for leaks. Ask for an itemized invoice, the warranty on parts and labour, and the model and serial numbers of anything installed, such as a water heater or sump pump.
• Keep it all together: the invoice, warranty, permit and photos are what you'll need for a warranty claim, an insurance claim, a city rebate or a future sale.
• Set a reminder for anything that needs upkeep, like testing a sump pump or flushing a water heater.

9. Red flags

• They won't give a name you can find on the public register.
• They want cash only, or full payment up front.
• They won't put the price in writing.
• They say the job needs no permit when it adds or moves plumbing.
• They knock on your door offering to replace a water heater or furnace. Ontario bans door-to-door sales of water heaters and furnaces unless you contacted the business first. See our water heater guide.

10. Help with the cost

Several cities pay back part of the cost of flood-protection plumbing like backwater valves and sump pumps, including Toronto, Mississauga, Peel, Halton, Hamilton, St. Catharines, Niagara Falls, Welland, Markham and Richmond Hill. Most need approval or a permit before the work starts. See our sump pump and backwater valve guide.