Guide · Plumbers

Licensed plumber,
in plain terms.

Plumbing in Ontario is regulated twice. The province decides who may do the work: plumber is a compulsory trade, so everyone on the tools needs a certificate or a registered apprenticeship. Cities can add a business licence on top, and Toronto's comes with a rule about what goes on your trucks, invoices and ads. Here is what the primary sources say, and what it means for your website.

Published 2026-11-04 · Formory Marketing Group

Section 2 of O. Reg. 876/21 lists plumber among the compulsory trades under the Building Opportunities in the Skilled Trades Act, 2021. Section 6 of the Act says no individual may practise a compulsory trade unless they are an apprentice working under a registered training agreement, hold a certificate of qualification or provisional certificate that is not suspended, or are exempted by regulation.

Section 7 puts the same duty on the business: no person may employ or otherwise engage an individual to do compulsory-trade work unless one of those conditions is met. An inspector who believes either section was broken can issue a notice of contravention with an administrative penalty under section 27.

The trade's scope, in section 103 of O. Reg. 875/21, covers installing, maintaining or repairing piping, fixtures and appurtenances for water supply or for disposing of used water, connecting appliances that use water, and making joints in piping. It does not include laying pipe in trenches to form sanitary or storm sewers, drains or water mains.

Skilled Trades Ontario files the plumber trade under code 306A. Its trade page sets the apprenticeship at 9,000 hours, about five years: 8,280 hours on the job and 720 in school. Passing the certifying exam earns a Certificate of Qualification, and plumber is a Red Seal trade.

Under section 3 of O. Reg. 877/21, a certificate in a compulsory trade lasts one year. Skilled Trades Ontario's certificate page puts the annual fee at $60 plus HST and says a wallet-card sticker showing the expiry date and account number is issued on renewal. Section 9 of the Act requires certificate holders and apprentices to carry proof and show it to an inspector on request.

Plumber is also one of the trades subject to an apprentice-to-journeyperson ratio under section 4 of O. Reg. 876/21. Section 8 of the Act sets the default at one apprentice for each journeyperson unless another ratio is prescribed.

Section 47 of the Act requires a public register of every apprentice and certificate holder in a compulsory trade, with any conditions, suspensions, revocations and Red Seal endorsements. Section 18 of O. Reg. 877/21 adds each person's Skilled Trades Ontario ID number, issue and expiry dates, and an active or expired status.

The Public Register is searched by all or part of a first or last name, or by ID number. It lists people, not companies. The same page tells the public where to report trade work by someone who may not be authorised: the Ministry's Occupational Health and Safety Contact Centre.

The provincial Act and its regulations do not use the title "master plumber". The provincial credential is the certificate of qualification, and the Act's word for a qualified worker is journeyperson.

"Master plumber" is a City of Toronto licence. Chapter 545 of the Toronto Municipal Code defines a master plumber as someone skilled in planning, superintending and installing plumbing, with a regular place of business in Toronto. Under section 545-415, an applicant must submit a provincial certificate of qualification. Under section 545-425, a master plumber may act for only one plumbing contractor at a time, and the contractor's name must be endorsed on the licence.

So "master plumber" on a website implies a specific Toronto licence. If nobody at your company holds one, the claim can be false or misleading, which section 74.01 of the Competition Act treats as reviewable conduct. "Licensed" is safest when you can name the certificate or licence behind it.

Section 545-2 requires a City licence for every plumbing contractor, plumber and master plumber, and for every drain contractor and drain layer. The code's definition of plumbing contractor includes anyone who solicits plumbing work or advertises as doing it, so an ad alone brings you in. Under section 545-424, only a licensed master plumber or the full-time employer of one may hold a plumbing contractor's licence, and all plumbing work must be under a master plumber's direct, personal supervision.

The City's Plumbing Contractor page lists a total of $495.12 for a new licence and $293.14 to renew; licences expire every year. Businesses that also install warm air, hot water or steam heating need the separate Plumbing & Heating Contractor licence, which asks for a TSSA Fuel Safety Certificate. Drain work, including weeping tile and septic systems, needs a Drain Contractor licence, and applicants must first hold a Drain Layer licence and pass a trade exam. Section 545-419 requires drain contractors to give an itemised account of hours and materials before taking payment.

Then the display rule. Section 545-420 requires every plumbing contractor and drain contractor to show "Toronto Licence No." followed by their trade number on both sides of every business vehicle, in letters at least 10 centimetres high and legible from six metres. The same inscription must appear on stationery, forms, bills, invoices, statements and any other printed or written advertising, including published ads in a newspaper, periodical or directory. Customers can check a City licence with the Business Licence Lookup.

Under section 851-8F of Toronto's Water Supply By-law, an owner may not let anyone test, install, repair or service a backflow prevention device unless that person holds a current Certificate of Achievement in Cross Connection Control endorsed by the Ontario Water Works Association, ASSE International or another approved body, has a current calibration certificate for the test gear, and is authorised under Schedule 6.

The City's Backflow Prevention Program asks plumbing contractors to register before testing, sending a City plumbing contractor licence, the certificate of qualification, the cross connection certification and a gauge calibration certificate under a year old. It also says devices must be installed by a plumber licensed with the City. Advertise backflow testing only once you are registered.

If you work in Toronto, put "Toronto Licence No." and your number in the footer of every page, on quote PDFs and invoices, and in your Google Business Profile description and ads. The by-law does not name websites, but its wording reaches any written advertising material and directory advertisements. Letter it on both sides of the van.

On the about page, name the people who hold the 306A certificate, with their consent, and tell customers they can check them on the Skilled Trades Ontario Public Register. Use "master plumber" only if someone holds that Toronto licence. List drain and backflow services only under the licences and registrations they need.

Water heaters and water softeners carry one more rule. Section 43.1 of the Consumer Protection Act, 2002 and section 35.1 of O. Reg. 17/05 make an agreement signed at the customer's home for these products void unless the customer contacted you first and asked you to come, for example by phone or online. A booking form gives you that record. For gas work see TSSA registration, and for the rest of a plumber's site, our notes on websites for plumbers.

This is a plain summary of the Building Opportunities in the Skilled Trades Act, 2021, its regulations and Toronto Municipal Code Chapters 545 and 851 as of November 2026, not legal advice; Skilled Trades Ontario and Toronto Municipal Licensing and Standards answer questions about specific certificates and licences.

• Building Opportunities in the Skilled Trades Act, 2021 — sections 6 to 10, 27 and 47 (e-Laws)
• O. Reg. 875/21: Scopes of Practice — section 103 (e-Laws)
• O. Reg. 876/21: Prescribed Trades and Related Matters — sections 2 and 4 (e-Laws)
• O. Reg. 877/21: General — sections 3 and 18 (e-Laws)
• Skilled Trades Ontario — Plumber (306A)
• Skilled Trades Ontario — Certificate of Qualification
• Skilled Trades Ontario — Public Register
• Toronto Municipal Code Chapter 545, Licensing — Article XXXIV (consolidated January 1, 2025)
• City of Toronto — Plumbing Contractor licence
• City of Toronto — Master Plumber licence
• City of Toronto — Plumbing & Heating Contractor licence
• City of Toronto — Drain Contractor and Drain Layer licences
• Toronto Municipal Code Chapter 851, Water Supply — section 851-8
• City of Toronto — Backflow Prevention Program
• Consumer Protection Act, 2002, s. 43.1, and O. Reg. 17/05, s. 35.1 (e-Laws)
• Competition Act, s. 74.01

Or call (416) 989-3208. One of us answers; there is no sales team.

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