How to Hire a Qualified Plumber in Ontario
Plumbing is a compulsory-certification trade in Ontario, so the tradesperson's qualification and the local permit are the two things worth verifying first. This checklist is written for Ontario homeowners.
Licensing in Ontario
Plumber is a compulsory-certification trade in Ontario, which means the person doing the work must hold, or be a registered apprentice working toward, a Certificate of Qualification in the plumber trade (trade code 306A), overseen by Skilled Trades Ontario. Unlike electrical work, there is no single province-wide plumbing contractor registry, so verification happens at the tradesperson and municipal level.
Many municipalities also require plumbing or drain contractors to hold a local business licence, and plumbing work usually needs a building or plumbing permit from your municipality. Requirements vary by city, so confirm both the tradesperson's certification and the local permit for your job.
1. Ask for the Certificate of Qualification
Plumbing is a compulsory-certification trade in Ontario. Confirm the tradesperson holds a Certificate of Qualification (306A) or is a registered apprentice working under a certified plumber.
2. Check for a municipal contractor licence and permit
Many Ontario municipalities license plumbing or drain contractors and require a permit for the work. Ask which permit your job needs and confirm the contractor pulls it.
3. Check insurance and WSIB coverage
A legitimate plumber carries liability insurance and WSIB coverage. Ask for proof, especially for work on water lines where a failure can cause major damage.
4. Get itemized written quotes from at least three contractors
Compare fixtures, materials, labour, and permit costs in writing. A much lower quote often excludes the permit or uses lower-grade fixtures.
5. Ask about the workmanship warranty
Confirm in writing how long the plumber guarantees the work, separate from the manufacturer warranty on fixtures or water heaters.
6. Read recent reviews and ask for local references
Look for recent reviews in your own city and ask for two local references for similar work, such as a repipe or a water-heater install.
Ready to start? Browse plumbers by Ontario city and use this checklist when you call.