Quebec Sales Tax for Contractors: GST, QST and Revenu Québec

Short answer: A registered contractor in Quebec charges 5% GST plus 9.975% QST on the whole invoice — labor as well as materials — and recovers the tax paid on supplies as input tax credits and input tax refunds. You are not the end consumer of what you install. Registration becomes mandatory once worldwide taxable sales by you and your associates pass $30,000 in a calendar quarter or across the four preceding quarters. Both taxes are handled by Revenu Québec.

If you have read anything about how contractors are taxed in the United States, unlearn it before you price a job in Montreal. There, a contractor is usually deemed the final consumer of the materials and charges the homeowner nothing. Quebec runs the opposite model. Federally, the Canada Revenue Agency sets the GST rules, but in Quebec it is Revenu Québec that administers the QST and the GST/HST together. Licensing sits with a different body, covered in Quebec contractor license requirements, and coverage in Quebec contractor insurance requirements.

Who actually administers sales tax for a Quebec contractor?

Revenu Québec. GST and QST registration go hand in hand here, and the two taxes are reported together rather than to two separate agencies: your registration numbers arrive together, your returns arrive together, and the office you call when something is wrong is provincial, not federal. Elsewhere in Canada the provincial layer is administered apart from the federal one. In Quebec you quote against a combined burden of roughly 14.975% under a single roof.

Is your labor taxable in Quebec, or only your materials?

Both. Revenu Québec applies the GST and QST to the sale of most property and services, and there is no carve-out exempting renovation or construction labor supplied to a private homeowner. On a bathroom rebuild the taxable amount is the whole contract price: your hours, your helper’s hours, your markup, the tile, the delivery charge you passed on.

Tax	Rate	Calculated on
GST	5%	The selling price
QST	9.975%	The selling price excluding the GST

That second row matters more than it looks. Because the QST is calculated on the price excluding the GST, the two taxes do not compound. A $5,000 job carries $250 of GST and $498.75 of QST for a $5,748.75 total — not the higher figure you would get by stacking one tax on the other.

Are you the final consumer of the materials you install?

Once you are registered, no. As a registrant you recover the GST and QST paid on property and services acquired for your commercial activity, through input tax credits (ITCs) for the GST and input tax refunds (ITRs) for the QST. Tax on lumber, fixtures, tools and subcontractor invoices flows back to you on your return. There is a deadline for claiming them, so a shoebox of unfiled supplier receipts does not wait indefinitely — confirm the current window with Revenu Québec before you write off an old purchase.

The exception is the one nobody plans for. If you are still a small supplier and have not registered, you pay tax on every purchase, cannot claim ITCs or ITRs, and charge your customer nothing. In that state you genuinely are the final consumer, and the tax you swallowed has to sit inside your labor rate — the honest reason to register early even when you are under the threshold.

One more edge: some supplies of immovables are exempt rather than taxable. Under section 94 of the Act respecting the Québec sales tax, the sale of a residential complex by a person who is not the builder of it is exempt, subject to stated conditions. Tax paid on inputs for an exempt supply is not recoverable, so an exempt transaction quietly costs you more than a taxable one.

When does GST and QST registration become mandatory?

Once you stop being a small supplier. Section 294 of the Act respecting the Québec sales tax keeps you a small supplier while taxable supplies made by you and your associates, inside or outside Québec, stay at or under $30,000 across the four immediately preceding calendar quarters.

The detail almost every summary gets wrong is that there are two ways past that line, and they bite at different moments.

How you cross $30,000	When you stop being a small supplier
In a single calendar quarter (s. 295)	Immediately before that sale — you charge tax on the very sale that took you over
Over the four preceding quarters, without exceeding it in any one quarter (s. 294)	Not until the end of that quarter plus the first month following it

So the panic response — “I just passed $30,000, I have to charge tax today” — is right only if you did it inside one quarter. Creep past the threshold slowly and the Act gives you the rest of the quarter and one further month before registration bites. Getting this backwards costs real money in both directions: charge too early and you have collected tax you had no authority to collect; charge too late and you owe tax you never billed.

Read “and your associates” carefully too. It is not just your own invoices, which catches contractors running a second numbered company or working alongside a spouse’s related business.

What has to appear on a Quebec contractor’s invoice?

Less than most people assume. The QST legislation prescribes no provincial invoice template for a framer or an electrician, and no construction-specific format. What it does require is that the tax be disclosed to the customer — either shown separately from the price or stated as included in it, and, if you show one combined tax figure, said plainly that the figure covers both taxes.

Your business customers are the real constraint. Their supporting documents must carry enough information to justify the ITCs and ITRs they claim, and how much is required scales with the value of the purchase. So both of your registration numbers belong on every invoice, with the date, a description of the work and the tax shown line by line — a subcontractor whose invoice omits them will be asked for a replacement before the general contractor’s own return is filed. Confirm the current documentary requirements with Revenu Québec, since they sit in regulation rather than in the Act. What to include on an invoice covers the rest.

What if you build or substantially renovate a home to rent out or live in?

Then you leave the ordinary contractor rules and enter the self-supply rules. Under section 223 of the Act respecting the Québec sales tax, a builder who substantially completes a single-unit residential complex or a residential unit held in co-ownership and then gives possession under a lease, or occupies it as their own residence, is deemed to have made and received a taxable supply of it by way of sale. Parallel sections do the same for complexes held in co-ownership and multiple-unit complexes.

The sting is the base. Tax is calculated on the fair market value of the complex — not on what it cost you to build — at the latest of substantial completion, the moment possession or use is given, and the moment it is first occupied as a residence. Registrants report it on their regular return; if you are not registered, ask Revenu Québec which return applies before the work finishes rather than after. If you occasionally build spec or hold a duplex, this is the Quebec rule most likely to produce an unbudgeted five-figure bill.

Do you have to collect an attestation de Revenu Québec from your subs?

Above a threshold, yes. Separate from rates and separate from your return, Quebec layers on a tax-compliance certificate that a subcontractor hands to the contractor hiring them. It is triggered by the value of the construction contracts between the two parties, and once the threshold has been crossed between them it carries over to their subsequent contracts regardless of size.

The regime reaches subcontractors with an establishment in Quebec whose work requires a licence under Chapter IV of the Building Act, and it applies through all tiers of subcontracting, not just the first. The subcontractor must give the contractor a valid copy within a fixed window around the start of the work, and penalties apply on both sides — the party who failed to hand one over and the party who failed to collect it.

The threshold and the deadline are set by tax legislation that Quebec amends periodically, so this is the wrong place to take a number from an article. Get the current dollar figure and the current window from Revenu Québec before you sign a subcontract. What does not change is the habit: in Quebec, hiring a sub means collecting a document as well as a quote.

How often do you file, and what does that ask of your records?

Revenu Québec assigns your filing frequency — monthly, quarterly or annual — based on total annual taxable sales in Canada by you and your associates, and prints it on your confirmation of registration. Monthly and quarterly returns are due no later than one month after the period ends. Annual filers generally remit in four instalments, unless the net tax expected for the year, or paid last year, is under $3,000.

Whatever your frequency, the return is only as good as two piles: tax charged out, and tax paid in. Miss a supplier receipt and you have overpaid; miss an invoice and you have underreported. How long to keep tax records sets the retention side.

Keel: Invoice Maker & Receipts, by Ilura Technology OÜ, is built for exactly that pair. It runs entirely on your iPhone — no account, no sign-in, no bank connection, no cloud sync — and its App Store privacy label reads “Data Not Collected.”

Be clear about the boundary: Keel is a record keeper, not a compliance tool. It does not register you with Revenu Québec, calculate your ITRs, file a return or issue an attestation. It produces numbered PDF invoices carrying your logo and a payment-link QR code, captures receipts read on device by Apple Intelligence, logs mileage, and holds everything in an append-only, hash-chained ledger the Accountant Pack exports as one file per year.

Free covers unlimited invoices, receipts and mileage. Keel Pro is a one-time $249.99 Lifetime purchase, not a subscription. Keel: Invoice Maker & Receipts on the App Store.

Frequently asked questions

Do Quebec contractors charge sales tax on labor? Yes. The GST and QST apply to the sale of most property and services in Quebec, and there is no exemption for construction or renovation labor supplied to a homeowner. The taxable amount is the full contract price — your hours, your markup and your materials together — at 5% GST plus 9.975% QST on the price excluding the GST.

Is a Quebec contractor the final consumer of the materials? Not once registered. A registrant recovers the GST and QST paid on business purchases through input tax credits and input tax refunds, so the tax on materials passes through rather than sticking. An unregistered small supplier is in the opposite position: tax paid at the counter is unrecoverable and has to be buried in the labor rate.

When do I have to register for GST and QST in Quebec? When taxable supplies by you and your associates, inside or outside Québec, pass $30,000. How fast it bites depends on how you crossed. Exceed $30,000 within a single calendar quarter and you stop being a small supplier immediately before that sale, so you charge tax on it. Exceed it only across the four preceding quarters and you stay a small supplier until the end of that quarter plus the following month. Registration for both taxes is done together through Revenu Québec.

Do I file GST separately from QST in Quebec? No. Revenu Québec administers both, and registrants report them together. Your filing frequency — monthly, quarterly or annual — is assigned on total annual taxable sales in Canada and shown on your confirmation of registration. Monthly and quarterly returns are due within one month of the period ending.

What is the attestation de Revenu Québec and does it apply to me? It is a tax-compliance certificate a subcontractor gives the contractor hiring them, required once the construction contracts between those two parties pass a dollar threshold, for work needing a licence under Chapter IV of the Building Act. It applies at every tier of subcontracting, and once triggered between two parties it carries into their later contracts. Take the current threshold and filing window from Revenu Québec, because both are set by legislation that changes.

Do I owe tax if I build a rental unit for myself? Possibly a large amount. Substantially completing a residential complex and then leasing it or occupying it yourself triggers the self-supply rules in section 223 of the QST Act: you are deemed to have both made and received a taxable sale, and tax is calculated on the fair market value of the complex rather than on your build cost. Registrants report it on their regular return; if you are not registered, ask Revenu Québec which return applies before the work is finished.

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This article is general information, not legal or tax advice. Rules change — confirm with the authority named above.