What does compulsory mean?
A compulsory trade is one where practicing without valid certification is an offence. Every compulsory trade has a certifying exam, and journeypersons in compulsory trades must renew their Certificate of Qualification every year. Whether a specific person is qualified can be checked on the Skilled Trades Ontario Public Register.
The other 121 prescribed trades are voluntary: you can work in them without a certificate, and certification serves as formal proof of competency. Note that voluntary status under this Act does not remove licensing that other statutes attach to specific work.
The full list, from O. Reg. 876/21, s. 2
Last verified August 19, 2026 against O. Reg. 876/21 as consolidated on e-Laws (consolidation period beginning January 1, 2022, no amendments). Trades without a linked record are outside the construction and industrial sectors this registry covers first.