General contractor subcontractor insurance requirements are mostly set by contract: the owner's contract sets what the general contractor must carry, and the general contractor passes those terms down to every subtrade. In Ontario, most GCs ask subtrades for $2M to $5M in commercial general liability, additional insured status and a waiver of subrogation, plus a valid WSIB clearance before anyone starts work. This guide covers what to ask for and how to check it.
Start with the owner's contract
Before you set a standard for subtrades, read the insurance section of your prime contract. Owners, lenders and their insurers often require the GC to carry specific limits, to name the owner and others as additional insureds, and to make sure every subcontractor carries matching coverage. If your subcontracts ask for less than the owner's contract requires, the gap is yours.
A common approach is a flow-down clause in each subcontract that incorporates the prime contract's insurance terms, followed by a schedule that lists the actual limits by trade. Keep the owner's named parties, such as the owner, its property manager and its lender, in the schedule so subtrades name them correctly.
Common general contractor subcontractor insurance requirements
None of these amounts are set by statute. They are typical terms in Ontario subcontracts:
- Commercial general liability (CGL): $2M per occurrence for most trades, and $5M or more for roofing, demolition, fire protection, restoration, elevator work, crane work and larger sites.
- Additional insured: the GC, and usually the owner and other parties named in the prime contract, added to the subtrade's CGL policy.
- Waiver of subrogation: the subtrade's insurer agrees not to pursue the GC or owner to recover a claim it has paid. Ask for it to appear on the certificate or an endorsement.
- Primary and non-contributory wording: the subtrade's policy responds first, before the GC's own policy.
- Automobile liability where vehicles or mobile equipment are used on site.
- Professional liability for design-build subtrades and engineers, and pollution liability for abatement and environmental work.
- Notice of cancellation, often 30 days.
For help choosing limits by trade, see how much liability insurance a contractor should carry.
WSIB clearance before work starts
In construction, a WSIB clearance certificate must be in place before any work begins and for the duration of the work. While it is valid, WSIB waives its right to hold you, as principal, liable for the subtrade's unpaid premiums. Without one, you can be held liable for those amounts. Clearances last up to 90 days and most expire on February 20, May 20, August 20 and November 20, so a long job will need several. Keep clearance records for at least three years.
WSIB coverage is also compulsory for independent operators, sole proprietors, partners and executive officers carrying on business in construction, with limited exemptions. A one-person subtrade who says they "don't need WSIB" usually does. You can check a clearance online in a few minutes.
Your duties as constructor
Under the Occupational Health and Safety Act, the constructor is the person who undertakes a project for an owner. On its project, the constructor must ensure that the required measures and procedures are carried out, that every employer and worker complies with the Act and regulations, and that workers' health and safety is protected. The constructor must also make sure each prospective contractor and subcontractor receives the owner's list of designated substances on site before entering a binding contract.
Insurance does not transfer these duties. It is one reason GCs also collect safety documents during prequalification, such as Working at Heights training records for workers who use fall protection, ESA licences for electrical subtrades and the subtrade's own safety program. Separately, the Construction Act requires each payer to retain a 10 per cent holdback, which is worth reflecting in subcontract payment terms.
Checking the certificate, step by step
- The named insured matches the legal name on the subcontract.
- Insurer, policy number, and effective and expiry dates are shown.
- Each limit meets your schedule for that trade.
- The GC, owner and other required parties appear as additional insureds, with exact legal names.
- Waiver of subrogation and primary and non-contributory wording appear where required.
- Coverage runs past the expected end of the work, or a renewal date is tracked.
- A current WSIB clearance is on file before mobilization.
A certificate of insurance shows coverage on the day it was issued. It does not guarantee the policy stays in force, so track every expiry date and request a renewed certificate before it passes.
Putting it into practice
Write one subtrade insurance schedule per project, tied to the prime contract, and send it with the tender package. Collect documents before the subcontract is signed, not on the first day on site. Outside Ontario, workers' compensation rules differ: look for a WorkSafeBC clearance letter, an Alberta WCB clearance letter or a CNESST attestation de conformité in Quebec. To find new subtrades, try the directory, and use the contractor compliance checklist to build your list. Vendorpass can track each subtrade's certificates and clearances across projects so expiries do not slip.