A CNESST attestation de conformité (certificate of compliance) is a document from Quebec's Commission des normes, de l'équité, de la santé et de la sécurité du travail that releases a hiring organization from potential liability for a contractor's unpaid workers' compensation assessment. CNESST describes it as an end of contract document: it must be obtained for each contract, and only this document releases the client from that liability. If you hire contractors in Quebec, or work there as a contractor, it is the closest equivalent to an Ontario WSIB clearance, but it works differently.
What the CNESST attestation de conformité covers
CNESST uses its own vocabulary. The business that hires another employer is the employeur donneur d'ouvrage (in CNESST's English material, simply the "employer"). The business that carries out the work is the entrepreneur (the "contractor"). If that contractor brings in another employer for part of the work, that business is a sous-traitant (subcontractor).
The attestation is about the contractor's dossier de financement, its file with CNESST for workers' compensation financing. For the file to be considered in compliance, CNESST says the contractor must file its Statement of Wages for insurable wages paid and file its remittances in line with the contract information provided, particularly the labour costs.
Like a WSIB clearance, it says nothing about the quality of the work, safety performance, liability insurance or trade licences. It is one document in a larger contractor file.
The client's liability it addresses
CNESST states that if you retain another employer for a contract and that employer does not pay the assessment it owes, you could be held responsible for paying it. The amount is calculated on the labour cost of the contract between you.
The attestation de conformité is how you close that exposure. CNESST is clear that a certificate is needed for each contract and that no other document releases the employeur donneur d'ouvrage from this liability. A contractor's general reputation, a letter from the contractor or an older certificate from a different job does not do the same thing.
Three services, three moments in a contract
CNESST offers three compliance verification services through MonEspace CNESST for employers, each tied to a stage of the work:
- Before the contract: validation de conformité (confirmation of compliance). Only the contractor can use it. If the file is compliant, the contractor gets immediate proof it can use when bidding. If not, CNESST explains why and what to do.
- During the contract: suivi de l'état de conformité (follow-up of compliance status). Both the employer and the contractor can use it to keep track of the contractor's compliance status while work is under way.
- At the end of the contract: attestation de conformité (certificate of compliance). Both parties can request it. This is the document that releases the employer from liability for that contract.
CNESST does not publish a fixed validity period for the attestation de conformité. It is issued per contract, at the end of the contract, so treat it as tied to a specific job rather than to a date range.
How to request and verify one
If you hire contractors, you can request the attestation yourself once the contract ends. When the employer makes the request, CNESST asks the contractor to confirm the contract details, and the contractor has 14 days to approve or object. If the contractor does not reply within that period, the information is considered confirmed. In practice, it helps to:
- Collect the contractor's Quebec enterprise number (NEQ) or CNESST employer number when you sign the contract. CNESST's request form asks for these for both parties.
- Keep a record of the contract value and the labour cost, since CNESST verifies the contract details and labour costs before issuing the certificate.
- Use the suivi de conformité service during longer jobs, so a problem surfaces before the final payment rather than after.
- Request the attestation at the end of each contract, and hold back final payment until you have it if your contract allows.
If you are a contractor, use the validation de conformité before bidding, keep your Statement of Wages and remittances current, and respond promptly when CNESST asks you to confirm a client's request. CNESST recommends making requests online. MonEspace CNESST for employers requires a clicSÉQUR Entreprises account, the Quebec government's authentication service.
Do not confuse this with the attestation de Revenu Québec, a separate document from Quebec's tax authority confirming that a business has filed its required tax returns and has no unpaid tax account (or is respecting a payment agreement). It is required for certain public contracts and certain construction contracts. It is not a workers' compensation document.
How it compares with a WSIB clearance
If you manage vendors in both Ontario and Quebec, the two documents serve a similar purpose but run on different logic. See what is a WSIB clearance certificate for the Ontario side.
| Item | Ontario WSIB clearance | Quebec CNESST attestation de conformité |
|---|---|---|
| Purpose | Waives the principal's liability for the contractor's unpaid premiums | Releases the employer from liability for the contractor's unpaid assessment |
| Timing | In construction, before work begins and for the duration of the work | At the end of each contract |
| Scope | Valid for up to 90 days from issue, renewable | Tied to a specific contract |
| Who requests | Contractor obtains it; principal can verify online | Employer or contractor can request it |
The practical difference: in Ontario you track a rolling expiry date, as covered in how long a WSIB clearance is valid. In Quebec you track contracts, and the key moment is closing each one out.
Keeping it current
Build the attestation into your contract close-out steps, alongside final invoices and deficiency lists, and keep a copy with each contract file. Use the contractor compliance checklist for the rest of the file. Vendorpass tracks clearance records per vendor, uses each province's own name for the document, and sends reminders before tracked dates lapse. For anything specific to your situation, check with CNESST directly.