How qst works
A business selling taxable goods or services in Quebec registers separately with Revenu Québec for a QST account, in addition to its GST/HST account already held with the Canada Revenue Agency. QST is charged on top of GST, calculated on the price before GST is added, so the two are stacked one after the other rather than combined into a single rate the way HST is in other provinces.
Revenu Québec, not the Canada Revenue Agency, receives and processes QST returns, which means a Quebec business tracks and files two separate tax filings, potentially on different schedules and deadlines throughout the year. Input tax refunds for QST paid on business purchases are claimed through the QST return the same way GST input tax credits are claimed separately on the federal return.
Example
A Montreal-based agency invoices a client $8,000 for services rendered that month. It charges 5 per cent GST ($400) and 9.975 per cent QST ($800), for a total of $9,200. The GST is remitted to the Canada Revenue Agency on the standard GST/HST return, while the QST is remitted separately to Revenu Québec, since Quebec administers its own provincial sales tax independently rather than through the federal system used elsewhere.
QST in QuickBooks Online vs Xero
QuickBooks Online applies both GST and QST tax codes automatically for businesses set to Quebec, tracking each separately for reporting purposes on its own line. Xero does the same, defaulting Quebec businesses to combined GST and QST codes that feed two distinct return summaries for the two separate tax authorities involved.
Common mistakes
- QST is calculated on the wrong base instead of being applied correctly, producing a tax total that does not match what Revenu Québec expects.
- A business assumes its GST/HST registration with the Canada Revenue Agency automatically covers QST, missing the separate registration required with Revenu Québec.
- The separate QST filing deadline with Revenu Québec is missed because the business is only tracking its federal GST/HST due date.
Why it matters
QST is administered entirely separately from federal GST, with its own registration, return and deadline through Revenu Québec, so treating it as a single combined tax creates compliance risk. A missed QST registration or filing exposes a Quebec business to provincial penalties that are completely independent of any federal GST issue. For businesses operating in Quebec, tracking the two tax systems separately keeps both authorities satisfied and protects cash flow from surprise assessments.
Related terms
How LedgerBPO handles qst
We code Quebec transactions with the correct GST and QST rates, reconcile both control accounts each period and prepare figures for the separate federal and Revenu Québec filings, ready for your or a registered filer's review each period.