Quebec is the only province where Revenu Québec, rather than the Canada Revenue Agency, administers the GST on behalf of the federal government. An IT contractor with a Quebec establishment, or a Quebec-resident sole proprietor, registers for both GST and QST through Revenu Québec, files both returns with Revenu Québec, and remits both amounts to Revenu Québec. The CRA registration process described for other provinces does not apply.
This article covers how QST registration works, where it differs from the federal GST framework, and what IT contractors need to understand before invoicing Quebec clients.
What QST is
The Quebec Sales Tax (QST) is Quebec’s provincial consumption tax on the supply of goods and services in Quebec. It applies at 9.975%, calculated on the pre-tax price of the supply. GST applies at 5% on the same base. The combined rate is 14.975%.
QST is governed by the Act Respecting the Québec Sales Tax, which closely parallels the federal Excise Tax Act but operates as a separate legal regime. Most of the concepts carry over: taxable supplies, exempt supplies, zero-rated supplies, and input tax recovery. The terminology is different. Where the federal system uses Input Tax Credits (ITCs), QST uses Input Tax Refunds (ITRs). The mechanics work the same way.
Registration threshold
The QST registration threshold is CAD $30,000 of taxable supplies, including zero-rated supplies, over four consecutive calendar quarters, consistent with the federal GST threshold. The two thresholds are independent, but in practice they are crossed at the same time. Most IT contractors on agency or direct contracts reach the threshold on their first or second invoice.
For an incorporated IT contractor, the threshold applies at the corporate level. The corporation registers, collects, and remits both taxes. The shareholder does not register personally unless they also have separate self-employment income billed directly.
The obligation to collect begins when the threshold is crossed, not when registration is complete. Revenu Québec can assess QST on invoices issued after the threshold was reached, even if the contractor did not collect it at the time. This retroactive liability risk is the same as under the federal GST/HST registration rules, and the exposure applies to both taxes simultaneously in Quebec.
Registering with Revenu Québec
Registration is done through Revenu Québec’s online registration portal. Registration can be completed through Revenu Québec for both GST and QST, usually as part of the same registration process. There is no separate CRA registration for GST in Quebec.
After registration, Revenu Québec assigns a GST registration number and a QST registration number. Both appear on invoices to clients. The GST number uses the same format as in other provinces. The QST number follows a different format: it ends in TQ0001 (or a similar suffix).
Input Tax Refunds
A registered QST vendor can claim Input Tax Refunds (ITRs) on QST paid for business purposes: professional fees, software subscriptions, office supplies, equipment, and other eligible business inputs. ITRs reduce the QST owing on each return, the same way ITCs reduce GST owing.
The eligibility rules for ITRs track the federal ITC rules closely. Business-use expenses qualify. Personal-use expenses do not. Mixed-use expenses require an apportionment. Documentation requirements are the same: invoices showing the supplier’s QST number and the QST charged.
For most IT contractors billing other businesses, the QST charged to clients is recoverable by those clients through their own ITRs. The tax is effectively neutral for business-to-business supplies. The net cost of collecting and remitting QST is administrative, not a direct pricing issue with business clients.
Filing frequency
Revenu Québec assigns a filing frequency based on annual taxable supplies, aligned with the federal GST filing frequency. Most IT contractors with revenue under CAD $1.5 million file annually. Quarterly and monthly filing applies at higher revenue levels.
Annual filers make quarterly instalment payments. See Revenu Québec’s filing frequency and instalment information for the current thresholds and payment schedule.
The GST return and the QST return are filed separately through Revenu Québec’s online portal. Both cover the same reporting period. Remittance is made to Revenu Québec for both amounts.
Zero-rating and place-of-supply rules
Services provided to clients outside Canada may be zero-rated where the export rules are met. Zero-rating means the tax applies at 0%, so the contractor charges no GST or QST on qualifying export supplies, but retains the right to claim ITCs and ITRs on related expenses. For IT contractors performing work remotely for non-resident clients, the export treatment is often available, but the specific contract and service arrangement should be reviewed to confirm.
For clients in other Canadian provinces, the issue is not export zero-rating. The contractor must apply the GST/HST place-of-supply rules to determine whether to charge GST at 5% or HST at the applicable provincial rate. A Quebec-registered contractor making a supply deemed to be made in a participating province, such as Ontario, is required to collect HST at that province’s rate, not GST at 5%. QST generally applies where the supply is made in Quebec. See CRA’s place-of-supply rules for how the rate is determined by supply type and client location.
How QST fits into the broader Quebec compliance picture
QST registration is one part of the broader compliance structure described in the Quebec IT contractors guide. An incorporated IT contractor with a Quebec establishment files corporate returns with both CRA and Revenu Québec, and the same single-agency relationship applies to consumption taxes: all GST and QST filings go through Revenu Québec, not CRA.
For sole proprietors in Quebec, QST filings are handled through Revenu Québec, while the TP-1 personal income tax return is also filed with Revenu Québec. These are separate filings, even though they are administered by the same agency. There is no CRA involvement in the QST filing regardless of whether the contractor is incorporated.
The compensation decisions that affect salary vs. dividend planning for incorporated contractors, covered in the salary vs. dividend guide, are separate from QST. QST applies to the supply of services, not to how the contractor draws income from the corporation.
Working with a CPA who handles both GST and QST filings alongside the income tax returns, and who is familiar with Revenu Québec’s processes and audit practices, reduces the risk of inconsistencies between the two systems and ensures that zero-rating positions are documented and supportable.