QST vs GST/HST: Key Differences, Registration, And When Each Applies

Quebec Sales Tax (QST) Quebec's value-added consumption tax administered separately from the federal GST/HST system. Understanding the distinctions between QST and the federal GST (or combined HST in provinces that use it) is essential for businesses that operate across provincial lines or sell to Quebec customers from outside the province.

At a high level, GST (Goods and Services Tax) is federal and administered by the Canada Revenue Agency, while QST is Quebec’s provincial consumption tax administered by Revenu Québec. They often apply to the same transactions but follow separate registration and filing processes. The interaction between them—particularly the rule that QST is calculated on amounts that include GST—creates practical differences in accounting and tax calculations.

Administration And Registration

GST/HST is administered centrally by the Canada Revenue Agency (CRA). Businesses register for GST/HST with CRA. QST requires a separate registration with Revenu Québec. A business operating in Quebec will generally need both accounts; failure to register with Revenu Québec when required can lead to assessments and penalties even if the business is registered for GST with CRA.

• Separate Accounts: Businesses must manage distinct registrations and reporting: one with CRA (GST/HST) and one with Revenu Québec (QST).
• Different Filing Rules: Remittance schedules and filing frequencies may differ between the two jurisdictions.
• Thresholds: Small-supplier thresholds influence registration; check both federal and provincial thresholds.

How The Taxes Are Calculated

Both are value-added taxes but the QST is typically calculated on the transaction amount that already includes GST, effectively producing tax-on-tax for combined transactions. This requires POS systems and accounting software to apply calculations in the correct sequence: calculate GST first, then calculate QST on the GST-inclusive amount where applicable.

• Tax Sequence: GST applied first, then QST calculated on the GST-inclusive price for most retail transactions.
• Invoice Presentation: Invoices should display GST and QST separately and show the calculation basis when required.

Place Of Supply Rules And Cross-Province Sales

Place of supply rules determine whether QST (or a different provincial tax) applies. If a sale is considered to be supplied in Quebec, QST applies; if the customer is outside Quebec, QST may not apply and the sale may be zero-rated or subject to the tax regime of the destination province. For e-commerce and remote sellers, accurate shipping records and place-of-supply analysis are critical.

• Remote Sellers: Online sellers must determine where the consumer receives the goods or services to decide applicability of QST versus GST/HST.
• Documentation: Proof of export or delivery outside Quebec supports non-application of QST.

Input Tax Recovery And Credits

Businesses registered for GST and QST normally recover the consumption taxes paid on inputs used in commercial activities via input tax mechanisms. The mechanics differ: businesses claim GST input tax credits with CRA and QST input tax refunds/credits through Revenu Québec. Proper invoicing and documentation are necessary to substantiate claims to each agency.

• Separate Claims: GST ITCs are claimed to CRA; QST input credits are claimed to Revenu Québec.
• Eligible Expenses: Only purchases used in commercial activities qualify; mixed-use items require proration.

When Each Applies — Typical Scenarios

If a business sells and ships goods within Quebec, both GST and QST generally apply. If goods are shipped from Quebec to another Canadian province, the supply may be zero-rated for QST or fall under the destination province’s rules. For cross-border sales to customers outside Canada, GST and QST treatment depends on export rules and evidence of export.

• In-Province Sale: GST + QST typically apply, collected and remitted separately.
• Interprovincial Sale: Determine destination province rules and whether QST applies.
• International Sale: Exports may be zero-rated, but supporting documentation is required to avoid assessments.

In short, the Quebec Sales Tax (QST) is a provincial value-added tax that operates alongside the federal GST/HST system but with different administration, calculation sequencing, and registration requirements. Successful compliance depends on distinguishing administration, following place-of-supply rules, and maintaining records for both taxes.