Onboarding a subcontractor in Ontario

Last reviewed 27 August 2026. Ontario construction.

Most offices collect the right documents. Far fewer verify them, and almost nobody diarizes the dates, which is why a file that was complete in March is half expired by August.

Before they set foot on site

• Signed subcontract or purchase order, with the insurance and WSIB requirements written into it rather than assumed. If your contract does not say what limit you require, you have nothing to hold them to.
• WSIB account number and a current clearance. In construction the clearance has to be in place before work begins and stay in place for the duration. Collect the account number as a number, not as a screenshot, because you will need it again every quarter.
• Certificate of insurance, showing the limit your contract requires and naming you as an additional insured if that is what you asked for.
• Health and safety documents your project requires: the policy, the safety record, and COR certification where the owner asks for it.
• HST registration number, for accounts payable rather than for risk.
• The legal name, spelled the way it appears on the WSIB account. This is the field that quietly breaks everything downstream. A business trading as "Grand Electric" whose account is under a numbered company will fail every clearance check you run under the trading name.

Verify, do not file

The difference between an office that is covered and one that is not is almost entirely here. Filing is receiving a PDF. Verifying is checking the document says what you needed it to say.

• Run the clearance yourself rather than accepting theirs. A certificate a contractor emails you is a certificate they pulled on a day of their choosing. Pulling it yourself is free and takes a minute.
• Read the insurance limit against the contract, and the named insured against the entity you actually signed with.
• Check the expiry dates are in the future. Certificates arrive already expired more often than anyone expects, usually because somebody forwarded last year's from their sent items.

The three dates to diarize

1. The clearance expiry. Mostly one of 20 February, 20 May, 20 August or 20 November. Set the reminder three weeks before, not on the day. See the quarterly dates.
2. The insurance policy expiry. Whatever the certificate says, on the policy's own anniversary, unrelated to anything else in your calendar.
3. Substantial completion or contract end. After which you stop chasing, but keep the records, because the evidence concerns work that has already happened.

What to keep, and for how long

Keep the document itself and the date you obtained it. What you want to be able to produce later is the page the WSIB served on a given date, and the certificate as the broker issued it, rather than a spreadsheet row saying the trade was fine.

The question an auditor or the other side's counsel asks is narrow: was this trade covered during the period this work was done? Answering it needs a record per period, not a record per trade. That is the reason a folder built at onboarding and never refreshed does not answer it, however carefully it was built.

The part nobody has time for

None of the above is difficult. It is just relentless, and it lands on one person in the office who also has four other jobs. Twenty trades, four times a year, is eighty lookups plus the chasing of whoever has not sent anything back, and the work arrives in the same three weeks every quarter.

That is the shape of the problem, and it is an administrative one rather than a legal one. What it needs is something that watches the dates without being asked.

Sources

• Questions and answers: Clearances, WSIB.
• Clearances, WSIB.