Is a plumber licensed in Ontario, and how do you check?
Yes. Plumber is a compulsory trade in Ontario: to work legally, a plumber must hold a Certificate of Qualification, a Provisional Certificate of Qualification or a registered training agreement, and must appear on the Skilled Trades Ontario Public Register, which you can search by name or Skilled Trades Ontario ID. A plumber who installs or services a natural gas or propane appliance also needs a gas technician certificate under O. Reg. 215/01.[1],[2],[3]
How to check
Search the Skilled Trades Ontario Public Register with all or part of the plumber's first or last name, or their Skilled Trades Ontario ID or account number. The register is how Skilled Trades Ontario confirms that a person can legally work in a compulsory trade.[2]
What Ontario's rules say
- Plumber is a compulsory trade in Ontario: to work legally, a plumber must hold a Certificate of Qualification, a Provisional Certificate of Qualification or a registered training agreement, and must appear on the Skilled Trades Ontario Public Register. Skilled Trades Ontario[1]
- Search the Skilled Trades Ontario Public Register by name or Skilled Trades Ontario ID to confirm a plumber can legally work in the trade. Skilled Trades Ontario[2]
- Under O. Reg. 215/01, only a certified gas technician may install, service or repair a natural gas or propane appliance such as a furnace; a G.2 certificate covers appliances of 400,000 Btu/h or less. Government of Ontario[3]
- In Toronto, installing or modifying a plumbing system, or installing a backwater valve, needs a building permit. City of Toronto[4]
- To qualify for Toronto's subsidy, the contractor must hold a valid City of Toronto business licence when the work is done, and a backwater valve needs a building permit and an inspection before it is covered up. City of Toronto[5]
Frequently asked questions
Does a plumber need a licence in Ontario?
Yes. Plumber is a compulsory trade, so a person practising it must hold a Certificate of Qualification, a Provisional Certificate of Qualification or a registered training agreement, and must appear on the Skilled Trades Ontario Public Register. A Certificate of Qualification in the trade must be renewed to stay valid.[1]
How do I check that a plumber is licensed?
Search the Skilled Trades Ontario Public Register by all or part of the plumber's first or last name, or by their Skilled Trades Ontario ID or account number. It exists to confirm that a person can legally work in a compulsory trade.[2]
Can a plumber install a gas water heater?
Only if they also hold a gas technician certificate. Under O. Reg. 215/01, no one may do a certificate holder's work without a certificate, and a G.2 certificate covers a natural gas or propane appliance with an input of 400,000 Btu/h or less.[3]
Does plumbing work need a building permit in Toronto?
Some does. The City of Toronto lists installing or modifying a plumbing system, and installing a backwater valve, among the projects that need a building permit. If you are claiming the city's Basement Flooding Protection Subsidy, the backwater valve must be inspected before it is enclosed or covered.[4],[5]
Does a plumber need a City of Toronto business licence?
For work you want covered by Toronto's Basement Flooding Protection Subsidy, yes: the contractor and any sub-contractors must hold a valid City of Toronto business licence when the work is done, or the funding is denied. The City's Business Licence Lookup tool, or 416-392-6700, will confirm it.[5]
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Sources
- Skilled Trades Ontario, Plumber (trade information). Accessed October 19, 2026.
- Skilled Trades Ontario, Public Register. Accessed October 19, 2026.
- Government of Ontario, O. Reg. 215/01: Fuel Industry Certificates. Accessed October 19, 2026.
- City of Toronto, When do I need a building permit? (Page modified July 21, 2026). Accessed October 19, 2026.
- City of Toronto, Basement Flooding Protection Subsidy Program (Page modified June 18, 2026). Accessed October 19, 2026.
This guide restates what each source says; it is not legal advice. Rules change — the linked source is the authority.
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