WSIB Clearance Certificate Liability Calculator
Pay a subcontractor without a valid clearance certificate and their unpaid premiums can become yours. Work out the exposure on each contract, when every certificate expires, and what your own premium looks like for the year.
premium that can transfer
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How the Exposure Is Built
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The Certificate Window
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Your Own Premium
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Points That Decide This
What to Do Next
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Disclaimer: Under the Workplace Safety and Insurance Act, a principal who engages a contractor is liable for the premiums owed by that contractor in respect of the work, unless the principal obtains a valid clearance certificate from the Workplace Safety and Insurance Board covering the period of the work. Mandatory coverage in the construction industry has applied to most independent operators, sole proprietors, partners and executive officers since 1 January 2013, subject to limited exemptions. A clearance certificate confirms only that the contractor is registered and in good standing on the date it is issued, and it is valid for a limited window, taken here as 90 days; a certificate that has expired does not protect payments made after its expiry. Premiums are calculated on insurable earnings, which exclude the materials portion of a contract, at the rate applicable to the contractor’s own rate group. The figures used in this calculator for the 2026 maximum insurable earnings per worker of $121,700 and the average premium rate of $1.23 per $100 have been supplied to us and postdate our verification; please confirm them and your own rate group against the current WSIB premium rate schedule before relying on any number here. Interest is an estimate only and the Board applies its own rates and methods. This page is general information, not legal or accounting advice.
The Premium Follows the Work, Not the Invoice
The rule that catches contractors is simple and unforgiving. If you engage a subcontractor and that subcontractor does not pay their WSIB premiums, the Board can look to you for them. You are the principal, you are registered, you are solvent, and you are in Ontario.
The protection is the clearance certificate. Obtain one covering the period of the work and the liability does not transfer. Pay without one and it can.
This is not a penalty for doing something wrong. It is a transfer of someone else’s premium onto your account, and it can arrive a year or more after the job finished, by which point the subcontractor has usually moved on. Recovering it from them is your problem, not the Board’s.
A Certificate Is a Window, Not a Permission Slip
The most common failure is not skipping the certificate entirely. It is obtaining one at the start of a job, filing it, and then paying on a contract that runs for eight months against a certificate that covered the first three.
A clearance certificate confirms the contractor’s standing on the day it is issued and holds for a limited window. Payments released after it expires are unprotected, even though a certificate exists in the file and everybody remembers getting one.
| Situation | Protected |
|---|---|
| Valid certificate covering the payment date | Yes |
| Certificate obtained, expired before the payment | No, for that payment |
| Certificate for a different contract | No |
| Subcontractor told you they are covered | No |
| Certificate obtained after the payment | No, it does not reach backwards |
Only the Labour Portion Is Insurable
Premiums are charged on insurable earnings, and materials are not earnings. On a supply-and-install contract the split matters a great deal: a $240,000 contract that is sixty per cent labour carries premium on $144,000, not on the full amount.
That makes the labour split worth stating in the contract rather than leaving to be argued afterwards. Where the contract is silent, the Board will apply its own assumptions, and those are rarely the ones that help you.
The subcontractor’s rate applies, not yours. A roofing subcontractor in a high rate group transfers premium at their rate even if your own rate group is far cheaper. That is why the exposure on a small contract can be larger than it looks.
Mandatory Coverage in Construction
Since January 2013, coverage has been mandatory for most people working in construction in Ontario, including independent operators, sole proprietors, partners and executive officers, subject to limited exemptions. The practical effect is that a subcontractor who says they do not need coverage because they work alone is usually wrong.
There is a narrow exemption for a corporation’s executive officers who do no construction work, and home renovators working directly for an occupant sit outside the requirement in some circumstances. Both are narrower than the people relying on them tend to assume, and neither is something to take on trust.
Where the Exposure Concentrates
- Long contracts paid in progress draws, where one certificate is obtained at the start and never refreshed
- Subcontractors who bring their own crews, since the earnings ceiling applies per worker and the exposure scales with headcount
- High rate group trades, where the premium per hundred dollars is several times your own
- Owner-operator subcontractors who believe mandatory coverage does not apply to them
- Jobs where the labour split was never documented, leaving the whole contract arguably insurable
- Final payments and holdback releases, which often go out months after the last certificate check
Holdbacks Are the Practical Control
The certificate check has to sit inside the payment process rather than beside it. A contractor who verifies at onboarding and never again has a control that works once. A contractor whose accounts payable system will not release a draw without a current certificate on file has a control that works every time.
The check is quick, it can be done online, and it costs nothing. The cost of skipping it is someone else’s premium bill with interest attached.
Getting a certificate after the fact does not help. It confirms standing on the day it is issued, so it cannot retroactively protect a payment already made. Once the money is out the door against no valid certificate, the exposure on that payment is fixed.
Your Own Premium Is a Separate Calculation
Alongside the transferred exposure sits your own premium, charged on your own insurable payroll at your own rate group, with the per-worker earnings ceiling applied to each worker separately rather than to total payroll.
That per-worker application matters for a small crew on high wages, because a business can be well under the ceiling in aggregate while several individual workers are over it. Applying the ceiling to the payroll total understates the premium.
What This Calculator Does Not Cover
- Whether a particular worker is an independent operator or your employee, which is a separate and often contested question
- Experience rating adjustments under the Board’s rate framework
- The narrow construction exemptions and whether a specific subcontractor qualifies
- Reporting and reconciliation obligations and the penalties for getting them wrong
- Appeals and objections where the Board has already transferred a premium to you
- CRA worker classification, which runs on different tests and can reach a different answer
If the Board has already billed you for a subcontractor’s premiums, the response window matters more than the amount. Our WSIB reporting and compliance service covers registration, reporting, clearance certificate controls and responding to a transferred premium assessment.
Frequently Asked Questions
Common questions on clearance certificates and subcontractor liability.
Related Calculators and Guides
More tools for contractors paying subcontractors.
Check It Before the Draw, Not After the Assessment
Send us your subcontractor list, the contract values and the certificate dates you hold. We will quantify the exposure on each one, set up a clearance check that sits inside your payment process, and respond to any premium the Board has already transferred to your account.