GST and QST Calculator for Quebec and Canada

How the GST and QST Calculator Works

The calculator automates the standard formulas used by Revenu Québec and the Canada Revenue Agency to determine sales tax amounts. You can enter any one value, such as the amount before tax, the total amount including tax, or a specific tax amount, and the tool will calculate the other two figures automatically. For a standard taxable sale in Quebec, the calculation follows a straightforward method. The GST amount is found by multiplying the pre-tax subtotal by 5%. The QST amount is found by multiplying the same pre-tax subtotal by 9.975%. The total amount including taxes is the sum of the subtotal plus the GST and QST amounts. This tool also functions as a reverse sales tax calculator, allowing you to work backwards from a final price to find the original subtotal and the tax breakdown.

It is critical to note that since January 1, 2013, the QST is calculated on the subtotal only, not on the subtotal plus the GST. This change harmonized Quebec's method with the federal system and prevents the double taxation that occurred under the old compound method. For a $1,000 service, the correct 2026 calculation yields $50.00 in GST and $99.75 in QST for a total of $1,149.75. The calculator uses the correct, non-compound method to ensure accuracy and compliance.

Current Sales Tax Rates and Rules for Quebec

In 2026, the sales tax rates in Quebec remain unchanged from previous years. The federal Goods and Services Tax is set at 5% across all of Canada. The provincial Quebec Sales Tax is set at 9.975%, leading to a combined effective rate of 14.975% on most taxable purchases. These two taxes are calculated independently on the same pre-tax subtotal. Quebec maintains its own distinct tax administration through Revenu Québec, separate from the federal Canada Revenue Agency that administers the GST. This means businesses operating in Quebec must manage two separate tax numbers, filing schedules, and remittance processes.

The requirement for a business to register for and charge QST is tied to the small supplier threshold. A business must register for QST if its worldwide taxable sales exceed $30,000 within four consecutive calendar quarters or within a single calendar quarter. This threshold is identical to the one used for GST and HST registration elsewhere in Canada. Businesses with sales at or below this $30,000 threshold are considered small suppliers and are not required to register, though they may choose to do so voluntarily. Once registered, a Quebec business receives a unique QST number in the format of 10 digits followed by 'TQ' and 4 more digits, such as 1234567890 TQ 0001.

• GST Rate: 5% federal tax across Canada.
• QST Rate: 9.975% provincial tax in Quebec.
• Combined Rate: 14.975% total sales tax in Quebec.
• Registration Threshold: $30,000 in taxable sales.
• QST Number Format: 10 digits + TQ + 4 digits.
• Administrator: Revenu Québec (QST) and CRA (GST).
• Calculation Base: Subtotal only for both taxes.
• Historical Change: QST moved to subtotal-only calculation in 2013.

Special Cases and Exemptions for Sales Tax

Not all transactions in Quebec are subject to the standard GST and QST rates. Several important exemptions and special tax rules apply to specific goods, services, and circumstances. For instance, most insurance premiums, such as those for auto and home insurance, are exempt from the standard 5% GST and 9.975% QST. Instead, a special 9% tax is applied directly to the insurance premium itself. This special tax is scheduled to increase to 9.975% on January 1, 2027, to align with the general QST rate. It is important to note that this tax on insurance premiums is not recoverable by businesses through Input Tax Refunds.

Other services have also been granted exemptions. As of June 20, 2024, counselling and psychotherapy services provided by defined practitioners are exempt from QST, aligning with federal GST exemptions to reduce costs for mental health support. Sales to First Nations individuals follow federal guidelines, with services provided on a reserve generally exempt from both GST and QST. The rules for used motor vehicles are particularly detailed. If purchased from a dealer, both GST and QST apply to the sale price. If purchased from a private individual, only QST is due, and it is calculated on the greater of the sale price or the vehicle's estimated value, paid directly to the SAAQ during registration.

As of January 1, 2025, the rule for using the estimated value was expanded. Previously applying to vehicles nine years old or less, it now applies to vehicles 14 years old or less. For vehicles 15 years or older, QST is generally calculated only on the agreed sale price. Transfers between related individuals, such as parents, children, or spouses, are often exempt from QST or taxed only on the sale price rather than the estimated value. By February 2026, this exemption is expected to extend to transfers from aunts and uncles to nephews and nieces.

Sales Tax Rates Across Canadian Provinces

Sales tax systems vary significantly across Canada, which affects how purchases are taxed for Quebec residents buying from other provinces. Quebec uses a dual tax system with separate federal and provincial components. Several other provinces use the Harmonized Sales Tax, a single tax that combines the federal portion with a provincial portion. In HST provinces, the GST is not charged separately. When a Quebec resident purchases goods or services from another Canadian province, the applicable sales tax depends on the supplier's location and registration status. For purchases made outside Canada, no GST or QST is charged at the time of sale, though customs duties and import taxes may apply when the goods enter the country.

Nova Scotia reduced its HST rate from 15% to 14% effective April 1, 2025. British Columbia has announced that selected professional services will become subject to its 7% Provincial Sales Tax beginning October 1, 2026. The federal GST rate of 5% is consistent nationwide, whether applied separately or as part of an HST. The small supplier threshold of $30,000 for mandatory GST/HST registration is also a federal standard that applies across Canada, including for QST registration in Quebec.

Business Obligations for GST and QST

For businesses operating in Quebec, managing sales taxes involves distinct responsibilities for both the federal GST and the provincial QST. Registration is mandatory once taxable sales exceed the $30,000 small supplier threshold in a rolling four-quarter period or any single quarter. A business must register separately with the Canada Revenue Agency for a GST/HST number and with Revenu Québec for a QST number. Both numbers must appear clearly on invoices issued to Quebec customers. Filing frequencies for QST returns are determined by annual sales volume, with monthly filing required for businesses with sales over $6 million, quarterly for sales between $1.5 million and $6 million, and annually for sales under $1.5 million.

The mechanism for recovering taxes paid on business expenses also differs between the two systems. For the federal GST, businesses claim Input Tax Credits when filing their GST return with the CRA. For the provincial QST, businesses claim Input Tax Refunds when filing their QST return with Revenu Québec. The rules are similar but are processed through separate government portals. Businesses that are not registered, such as small suppliers below the threshold, cannot claim these refunds on their purchases. Furthermore, under Quebec's Bill 96, commercial documentation including invoices must be available in French, with French being at least as prominent as any other language used.

• Registration Threshold: $30,000 in worldwide taxable sales.
• Separate Numbers: GST number from CRA, QST number from Revenu Québec.
• Filing Frequency: Monthly, quarterly, or annual based on sales volume.
• Tax Recovery: Input Tax Credits (GST) and Input Tax Refunds (QST).
• Invoice Language: French must be available and prominent.
• Construction Rule: RBQ licence number required on invoices.
• Voluntary Registration: Allowed for businesses under the threshold.

The Financial Impact of Sales Taxes

Sales taxes represent a major source of revenue for both the Quebec and federal governments. Based on the Quebec budget for the 2025-26 fiscal year, revenue from consumption taxes like the QST is projected to be $28.922 billion. This amount constitutes 23% of all of Quebec's own-source revenue, excluding federal transfers. To put this in perspective, QST revenue is equivalent to over 60% of Quebec's total personal income tax revenue. At the federal level, the Goods and Services Tax is estimated to generate about $55.3 billion in revenue during the 2024-25 fiscal year, accounting for 10.8% of total federal government revenue.

The historical evolution of these taxes also highlights their significance. The federal GST was introduced on January 1, 1991, at an initial rate of 7% before being reduced to its current 5%. Quebec consolidated its provincial sales tax into the QST in 1994, starting at a rate of 6.5% and gradually increasing to the current 9.975% set in 2013. The 2013 change in the QST calculation method, moving from a compound to a subtotal-only base, was a significant administrative shift designed to harmonize with the federal approach and simplify the tax structure for businesses operating across provincial lines.

Frequently asked questions

Sources and further reading

1. Quebec Sales Tax (GST & QST) Calculator 2026 wowa.ca
2. Sales tax calculator, GST and QST 2026 calculconversion.com
3. GST Calculator Canada | HST, PST & Reverse Sales Tax gstcalculator.ca
4. GST/QST Calculator,, Quebec Sales Tax 2026 ibill.ca
5. 2026 GST/QST Calculator: Sales Taxes in Canada en.bankeo.ca

This article explains how things work and is not financial, tax or legal advice. Rules, limits and rates change, so check the current figures with the Canada Revenue Agency, your province or your financial institution before you act.