Is the GC legally responsible for a sub’s untrained worker?

Frequently, yes. Ontario’s OHSA places project-wide duties on the constructor, and OSHA’s multi-employer policy lets controlling contractors be cited alongside the employing sub. Liability is shared in law and asymmetric in practice — the GC’s name is on the project.

How often should sub documents be re-verified?

Match each document’s own cycle: WSIB/WorkSafeBC clearances every 90 days or per draw, insurance at renewal, worker certificates continuously via expiry tracking. A fixed annual re-check guarantees you are stale most of the year.

Can we make the sub responsible by contract?

You can — and should — assign the training duty and documentation duty by contract. But regulatory duties on constructors and controlling contractors cannot be contracted away, so the practical answer is contract language plus visibility, not contract language instead of it.

What if a sub refuses to share worker certifications?

Treat it as the readiness gap it is: workers whose required credentials cannot be verified are not site-ready under your own gate rules. Most refusals are logistics, not resistance — a system where workers carry their own records removes the sub’s admin burden entirely.

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Construction Compliance

Managing Sub-Contractor Certifications Without the Blind Spot

Published 2026-07-15·Last reviewed 2026-07-15·Reviewed by the WorkSitePass Compliance Team·6 min

Managing sub-contractor certifications means treating a sub’s credentials as a standing requirement — visible to you, current, for the life of the contract — instead of a one-time package collected at signing. The GC rarely trains the sub’s workers, but on a multi-employer site the GC carries constructor-level responsibility when an untrained one gets hurt, which makes “their office handles it” the most expensive sentence in construction.

Why are sub-trade certifications the classic blind spot?

Because nobody owns them end to end. The sub’s employer owns the training; the GC owns the site; the worker owns the card. Each party reasonably assumes another is checking — and the result is that sub-trade credentials are the documents a GC is least likely to have ever seen, on the workers most likely to rotate without notice.

The exposure is not theoretical. On Ontario projects the constructor must ensure that every employer and worker on the project complies with the OHSA — “we assumed the sub handled training” has never been a defence. The same logic applies under OSHA’s multi-employer citation policy: controlling contractors can be cited for hazards created by subs.

What should a GC collect from every sub?

Two layers, same as your own compliance. Company documents: workers’ compensation clearance (WSIB, WorkSafeBC, or CNESST depending on province) and a Certificate of Insurance naming appropriate coverage — both current, not photocopies from last year’s bid. Worker credentials: the specific certifications your site requires for the trades the sub is deploying — heights, WHMIS, first aid coverage, equipment tickets.

Collect against the site’s requirements, not against a generic list. A drywall sub’s crew and a roofing sub’s crew have different mandatory tickets; asking every sub for everything produces piles of paper nobody reviews.

Why do one-time compliance packages fail?

A package collected at contract signing is a photograph of a moving target. Clearance certificates lapse in 90 days; insurance renews annually; worker certificates expire on their own schedules; and the crew that shows up in month four often isn’t the crew whose certificates are in the binder.

During manual verification we see the month-four problem constantly: the documents on file are genuine, current — and belong to workers who are no longer on the site. The package didn’t fail; the assumption that a snapshot stays true did.

What does a standing requirement look like in practice?

Three properties: the sub’s documents live somewhere the GC can see without asking; expiries alert both parties before they land; and new workers joining the sub’s crew are checked against the site’s requirements at assignment, not discovered at the gate.

Contract language helps — make current documentation a payment condition, not a courtesy — but the mechanism matters more than the clause. A shared system where the sub’s workers carry their own verified credentials removes the whole collect-chase-recollect cycle: the GC checks readiness instead of collecting paper.

Frequently Asked Questions

Related Resources

Guide

Construction Compliance for Small & Mid-Size GCs

The two compliance layers this guide builds on.

Certificate

Workers’ Compensation Clearance

The 90-day document every sub must keep current.

Certificate

Certificate of Insurance (CGL)

What to require and what to check.

Field Notes

The Sub-Trade Blind Spot

The field story behind this guide.

Field Notes

Who Owns the Risk?

How liability actually splits between the GC and the sub.

Product

WorkSitePass Sites

Standing per-site requirements with readiness visibility.

Product

WorkSitePass Plans

14-day free trial, no credit card.

Next in this series

How to Prepare for a Construction Safety Audit