Why these questions
In Ontario, a contractor who hires a subcontractor without a valid WSIB clearance certificate can be held responsible for the premiums that sub owes WSIB (Workplace Safety and Insurance Act, section 141). A clearance certificate shows the sub is registered and in good standing on the day it was issued, and each one carries a validity period, so it has to be checked again before it runs out and before you release each payment.
Since 2013, most people who work in construction in Ontario must have WSIB coverage, including independent operators, sole proprietors and partners. A one-person crew is not exempt just because it has no employees.
A certificate of insurance shows the sub's commercial general liability policy: insurer, policy number, limits and expiry date. Most general contractors ask for at least CA$2 million per occurrence and to be named as an additional insured, and many owners require CA$5 million on larger jobs. Check that the policy dates cover the whole job, not just the day the certificate was printed.
The full list of what to keep is on the printable checklist, and payment dates are worked out in the holdback calculator.
Keeping it current without chasing
SubProof gives each subcontractor a private upload link, no account needed. It reads the expiry dates you enter, shows every sub as covered, expiring or expired, and emails the sub 30, 14 and 7 days before a document runs out and on the day. You get a Monday summary of who needs attention before you approve the week's payments.
The score is a guide to where your paperwork is thin, not a legal finding. The dollar figure is a rough estimate from the numbers you enter; WSIB's actual assessment depends on the sub's payroll, rate group and history. General information, not legal or insurance advice.