If you hire a commercial cleaning company in Quebec, you can be held responsible for the workplace insurance premiums that company fails to pay the CNESST on your work. The law gives you a way out: get an attestation de conformité from the contractor, issued by the CNESST, and keep it on file when the contract ends or renews. Without it, an unpaid assessment can land on your desk months or years after the cleaners have gone.
This guide is for property managers, office managers and facility teams in Greater Montréal and the rest of Quebec who sign or renew cleaning contracts. It explains where the rule comes from, which documents count, and how to build the check into your purchasing routine.
Where the liability comes from
The rule sits in section 316 of the Act respecting industrial accidents and occupational diseases (Loi sur les accidents du travail et les maladies professionnelles, often shortened to LATMP). Under it, an employer that has work done by a contractor can be held jointly liable with that contractor, and with any subcontractor, for the assessments owed to the CNESST for that work.
Every Quebec employer pays these assessments to fund the workplace injury insurance plan. A cleaning company's premium is tied to its payroll, and building maintenance is a labour-heavy trade, so the amounts are not trivial. If the contractor stops paying, closes, or simply under-declares the payroll attached to your building, the CNESST can turn to you as the client and claim what it is owed.
Two points surprise most buyers:
- The type of contract does not matter. Administrative tribunal decisions have treated service contracts and contracts for work the same way under this section. A monthly janitorial agreement is squarely in scope.
- Ending the relationship does not end the exposure. A client cannot avoid the claim by saying it no longer does business with the contractor. The liability attaches to the work that was performed.
The document that protects you
The CNESST issues an attestation de conformité (certificate of compliance) to an employer whose file is in order. When a contractor gives you a valid attestation covering the end of the work, you are released from joint liability for that contractor's assessments.
Be careful with look-alikes. The CNESST also answers requests for a validation de conformité, and its own form states that a validation does not release the client from paying the contractor's assessment. A screenshot from an online portal, a line in a proposal saying "CNESST compliant", or a registration number on an invoice are not the same thing either. Only the attestation does the job.
Tribunal decisions have also faulted clients who relied on an old photocopy. Keep the original document you received, or one you can verify, and check that the employer name and file number match the company you actually pay.
When to ask for it
The attestation that matters is the one dated at the end of the work. That is easy on a one-time job such as a post-construction cleanup or a floor stripping project: you hold the final payment until you receive it.
Recurring cleaning is different, because the work never really ends. Sensible habits for ongoing contracts:
- At signing, ask for a current attestation as part of the bid package, alongside the insurance certificate.
- At each renewal or anniversary, ask for a fresh one. Many buyers do it once a year, and quarterly for larger sites.
- When the contract ends for any reason, ask for one before you release the last payment.
- When a subcontractor appears, ask your contractor how they manage the same check with that subcontractor, since the joint liability extends to them.
The Canadian Federation of Independent Business suggests a practical fallback: if the attestation is late, hold back an amount large enough to cover the premiums that might be owed until it arrives. Put that right in the contract so it is not a negotiation later.
Contract language worth adding
You do not need a lawyer to make this routine, though one can tighten the wording. A few clauses do most of the work:
- The contractor must provide a valid CNESST attestation de conformité at signing, at each renewal, on request, and before final payment.
- The client may withhold a stated amount, or the final payment, until the attestation is received.
- The contractor must obtain the same document from any subcontractor and provide it on request.
- The contractor declares that it pays employees according to the applicable rules, including the Montréal building maintenance decree where the building falls inside its territory.
That last point is related. Decree rates and CNESST premiums are both tied to payroll. A bid that seems too cheap to cover the decree wage often also hides an under-declared payroll, which is exactly the situation where an assessment goes unpaid.
Other checks that belong in the same file
While you are collecting the attestation, the rest of a compliant contractor file takes about ten extra minutes:
- Enterprise registration. Look up the company's Quebec enterprise number (NEQ) in the Registraire des entreprises to confirm the legal name and that it is active.
- Liability insurance. Ask for a certificate naming your organization as an additional insured, with limits that fit your building and the contract value.
- Safety documents. Under Quebec's workplace health and safety rules, cleaning chemicals used on site must come with labels and safety data sheets (SIMDUT, Quebec's name for WHMIS). Ask for the list of products and their sheets.
- Public contracts. Public bodies in Quebec require an attestation from Revenu Québec for contracts at or above $25,000. If you manage a public building, that document is a separate requirement on top of the CNESST one.
For what a full scope and price structure should look like before you compare bids, see our page on commercial cleaning in Montréal.
Frequently asked questions
Can a building owner be billed for a cleaning company's unpaid CNESST premiums?
Yes. Section 316 of the LATMP allows the CNESST to hold the client jointly liable with the contractor for assessments owed on the work done for that client. The attestation de conformité, obtained at the end of the work, is how you are released from that liability.
Is a CNESST validation de conformité enough?
No. The CNESST states on its own form that a validation response does not release the client from paying the contractor's assessment. Ask specifically for the attestation de conformité.
How often should you request the attestation on a monthly cleaning contract?
There is no single legal schedule for recurring service, so build one into the contract. A common approach is to collect it at signing, at every renewal or yearly anniversary, and before the final payment when the contract ends, with quarterly requests on larger sites.
Does this rule apply outside Quebec?
The CNESST and section 316 are specific to Quebec. Other provinces have their own workers' compensation boards and their own clearance processes, such as the clearance certificates issued by the WSIB in Ontario, so check the rules for the province where the work is done.
Get a cleaning quote with the paperwork included
Simple Service is registered with the CNESST, carries $5M in general liability insurance with a $10M umbrella, and our employees are bonded. We provide the compliance documents with every proposal for buildings in Greater Montréal. Tell us about your facility through our quote form and we will send a scope and price you can check line by line.