Plumbing Licensing in Ontario
Plumbers must hold a Certificate of Qualification issued by Skilled Trades Ontario. Plumbing work typically requires municipal permits and inspections.
At a Glance
Key licensing facts for plumbings in Ontario
Trade Classification
Compulsory Trade
License Required
Apprenticeship
9,000 hours
~5 years
Certification
Certificate of Qualification (C of Q)
Red Seal
Available
Interprovincial mobility
Permits
Typically required
Municipal Plumbing Permit, Municipal Building Permit
Insurance
Required/Expected
Licensing Requirements
Plumbing is a compulsory trade in Ontario under the Building Opportunities in the Skilled Trades Act (BOSTA). Plumbers must hold a valid Certificate of Qualification (C of Q) issued by Skilled Trades Ontario. The apprenticeship is 9,000 hours (approximately 5 years), consisting of 8,280 hours of on-the-job training and 720 hours of in-school training. Plumbing work typically requires municipal permits and inspections. Red Seal endorsement is available.
How to Verify
Ask for their Certificate of Qualification number and verify through Skilled Trades Ontario's online verification tool.
Permits You'll Need
Required permits for plumbing work in Ontario
Municipal Plumbing Permit
Required for most plumbing work in Ontario. The plumbing contractor applies for the permit and arranges inspections with the local municipality.
Municipal Building Permit
Required when plumbing work is part of a larger project that involves structural changes such as additions, basement underpinning, or new construction.
Plumbing inspections are required before walls and floors are closed up. Concealing uninspected plumbing is a code violation.
A backwater valve installation often requires a separate plumbing permit and is highly recommended for basement flood prevention.
Homeowner Tip
Contact your local municipal building department before starting any plumbing project to confirm which permits are required in your area.
Permit requirements vary by municipality. Always confirm with your local building department before starting work.
Red Flags to Watch For
Warning signs when hiring a plumbing
No Certificate of Qualification - this is a compulsory trade in Ontario
Refuses to provide a written quote or only gives vague verbal estimates
Pressures you into immediate, expensive repairs without explaining alternatives
No WSIB coverage or liability insurance
Suggests unpermitted work to save money on permits
Questions to Ask Before Hiring
Ask these before signing any contract
Do you hold a Certificate of Qualification from Skilled Trades Ontario?
Do you carry liability insurance and WSIB coverage? Can I see proof?
Will you provide a written, itemized quote before starting work?
Do you offer a warranty on parts and labour?
Will permits be required, and will you handle pulling them?
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Frequently Asked Questions
Do plumbings in Ontario need a licence?
Plumbing is a compulsory trade in Ontario under the Building Opportunities in the Skilled Trades Act (BOSTA). Plumbers must hold a valid Certificate of Qualification (C of Q) issued by Skilled Trades Ontario. The apprenticeship is 9,000 hours (approximately 5 years), consisting of 8,280 hours of on-the-job training and 720 hours of in-school training. Plumbing work typically requires municipal permits and inspections. Red Seal endorsement is available.
How can I verify a plumbing's credentials in Ontario?
Ask for their Certificate of Qualification number and verify through Skilled Trades Ontario's online verification tool.
What are the red flags when hiring a plumbing?
(1) No Certificate of Qualification - this is a compulsory trade in Ontario (2) Refuses to provide a written quote or only gives vague verbal estimates (3) Pressures you into immediate, expensive repairs without explaining alternatives (4) No WSIB coverage or liability insurance (5) Suggests unpermitted work to save money on permits
What questions should I ask before hiring a plumbing?
(1) Do you hold a Certificate of Qualification from Skilled Trades Ontario? (2) Do you carry liability insurance and WSIB coverage? Can I see proof? (3) Will you provide a written, itemized quote before starting work? (4) Do you offer a warranty on parts and labour? (5) Will permits be required, and will you handle pulling them?
What permits do I need for plumbing work in Ontario?
For plumbing work in Ontario, you may need the following permits: Municipal Plumbing Permit, Municipal Building Permit. Contact your local municipal building department before starting any plumbing project to confirm which permits are required in your area.
Should my plumbing have insurance?
Yes, plumbings in Ontario are expected to carry liability insurance and WSIB coverage.
What is the Red Seal endorsement for plumbings?
The Red Seal endorsement is a nationally recognized certification that allows tradespeople to work across all Canadian provinces and territories without additional testing. A Red Seal-endorsed tradesperson has met a standardized level of competency.
How much does a plumbing cost in Ontario?
Typical rates for plumbings in Ontario range from $90-$200/hour. Type and complexity of the job, accessibility of pipes, whether permits are required, emergency vs. scheduled service (emergency rates are 1.5-2x standard), age and condition of existing plumbing, fixture quality, and whether the home has older lead or galvanized pipes that need replacement.
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