Key takeaway: in Quebec, a construction quote adds the 5% GST and the 9.975% QST, both calculated on the price before taxes (the QST is not calculated on the GST), for a total of 14.975%. A small supplier, whose taxable supplies do not exceed $30,000 per calendar quarter or over four quarters, does not have to collect them.
What are the GST and QST rates in 2026?
In Quebec, the GST is 5% and the QST is 9.975%. The Canada Revenue Agency (CRA) rate table shows 5% for Quebec, which does not apply the HST, and 9.975% for the provincial tax (last update shown: April 1, 2025). The two taxes add up to 14.975% of the price before taxes. Revenu Québec also administers the GST in its territory: a Quebec business generally files its returns with Revenu Québec. This article is for a business registered in Quebec that invoices work in Quebec.
| Tax | Rate | Calculated on |
|---|---|---|
| GST (federal) | 5% | The price before taxes |
| QST (Quebec) | 9.975% | The price excluding the GST |
| Total of both taxes | 14.975% | The price before taxes |
How do you calculate the GST and QST on a quote?
Calculate the GST and the QST each on the price before taxes, then add them up. Revenu Québec specifies that the QST is calculated on the price excluding the GST: you never apply it to an amount that already includes the GST.
- Add up the taxable items in the quote (materials, labour, etc.): this is the price before taxes.
- GST = price before taxes × 0.05.
- QST = price before taxes × 0.09975.
- Total = price before taxes + GST + QST, or price before taxes × 1.14975.
| Item | Amount |
|---|---|
| Materials | $5,200.00 |
| Labour | $3,200.00 |
| Price before taxes | $8,400.00 |
| GST (5%) | $420.00 |
| QST (9.975%) | $837.90 |
| Total | $9,657.90 |
This fictitious example assumes all items are taxable. The mistake to avoid: calculating the QST on $8,820.00 (price plus GST) would give $879.80, which is $41.90 too much. For rounding, Revenu Québec states that a fraction of $0.005 or more is rounded up to $0.01; its example: for a $3,150 subtotal, the GST is $157.50 and the QST is $314.21 ($3,150 × 9.975% = $314.2125).
How do you find the price before taxes from a total that includes taxes?
Divide the total by 1.14975. This is a calculation derived from the two rates, not a rule specific to Revenu Québec. Fictitious example: $9,657.90 ÷ 1.14975 = $8,400.00; the GST is then $420.00 and the QST $837.90.
Do you always have to charge GST and QST? The $30,000 threshold
No: a small supplier does not have to register or collect the GST and QST. According to Revenu Québec, this is the case for a business whose taxable supplies made worldwide by itself and its associates do not exceed $30,000 in a given calendar quarter or over the four preceding calendar quarters (taxes, financial services and sales of capital property are excluded from the total). The CRA applies the same $30,000 threshold.
- Threshold exceeded in a single quarter: you immediately stop being a small supplier and must collect the taxes on the sale that exceeds the threshold and on all following sales.
- Threshold exceeded over four quarters: the status generally ends at the end of the calendar month following those four quarters.
- Below the threshold: you can still register; it lets you recover the taxes paid on purchases, but you must then stay registered for at least one year.
So track your taxable supplies quarter by quarter.
When must you collect the GST and QST?
On the earlier of two dates: the day the amount is paid or the day it is due. According to Revenu Québec, an amount is due at the earliest of these dates: the day you send the first invoice, the date shown on the invoice, the day you would have sent it without unreasonable delay, or the due date set in a written agreement. Each deposit follows the same rule. The CRA applies the same principle: payment or due date, whichever comes first.
In practice, the quote presents a price; it is the payment, the invoice or the contract's due date that makes the taxes payable. For the sale or construction of a building and other special situations, the rules may differ: check with Revenu Québec or your accountant. For a residential renovation job, see also our legal guide to renovation quotes.
What information must appear on the invoice?
No invoice format is imposed (except for restaurants and taxi operators), but the required information depends on the total, taxes included. According to Revenu Québec:
| Invoice total | Information to include |
|---|---|
| Less than $100 | Supplier's name, date, total amount and QST amount, with a description of the good or service (required for the QST); registration numbers not required |
| $100 to $499.99 | Add the GST and QST amounts and the supplier's GST and QST registration numbers; the description of the good or service is still required for the QST |
| $500 or more | Add the buyer's name (or their agent's) and the payment terms; the description of the good or service is then also required for the GST |
The CRA sets the same $100 and $500 thresholds for the GST. The GST number has 9 digits, followed by "RT" and 4 digits (format: 123456789 RT 0001); the QST number has 10 digits, followed by "TQ" and 4 digits (format: 1234567890 TQ 0001). These sample numbers are fictitious. Revenu Québec offers a service to check the validity of a QST number.
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How do you recover the GST and QST paid on purchases?
A registered business can recover the taxes paid on purchases related to its commercial activities. The input tax credit (ITC) covers the GST and the input tax refund (ITR) covers the QST; they are claimed in your returns, and the recoverable amount depends on the commercial use of the good or service. Your purchase invoices must contain the information in the table above. Special cases (meals, capital property, purchases made before registration) call for your accountant's advice.
Frequently asked questions
What are the GST and QST rates in Quebec in 2026?
The GST is 5% and the QST is 9.975%, for a total of 14.975% on the price before taxes. Revenu Québec specifies that the QST is calculated on the price excluding the GST.
How do you calculate the GST and QST on a quote?
Multiply the price before taxes by 0.05 for the GST and by 0.09975 for the QST, then add both amounts to the price. Fictitious example: $8,400.00 before taxes gives $420.00 of GST, $837.90 of QST and $9,657.90 in total.
When do you have to start charging GST and QST?
A small supplier, whose taxable supplies do not exceed $30,000 in a given calendar quarter or over the four previous calendar quarters, does not have to collect the taxes. If the threshold is exceeded in a single quarter, the status ends immediately.
When do the taxes become payable?
On the earlier of two dates: the day the amount is paid or the day it is due, for example the date of the first invoice sent or the due date set in a written agreement.
What information goes on a construction invoice?
No format is imposed. From $100, the invoice shows the supplier's name, the date, the total, the GST and QST amounts and the supplier's registration numbers; from $500, the buyer's name and the payment terms are added. For the QST, a description that identifies the good or service is required on even the smallest invoice; for the GST, it is required from $500.
And where does SubmitX fit in?
In SubmitX, the GST (5%) and QST (9.975%) are calculated automatically on quotes and invoices in Quebec, and recalculated every time a line changes. AI prepares a draft quote that you review before it goes out; SubmitX replaces neither your accountant nor Revenu Québec. For a quick calculation, use the GST and QST calculator, and to set your prices, the margin calculator. Another prerequisite before bidding: the RBQ licence. 7-day trial with no credit card; Free, Starter and Pro plans, pricing on request (Pricing).
Sources
Official pages consulted on October 13, 2026:
- CRA: GST/HST calculator (and rates)
- CRA: RC4022, General Information for GST/HST Registrants
- CRA: GST Memorandum 300-6-4, Agreements in Writing (when the tax is payable)
- Revenu Québec: Calculating the taxes (in French)
- Revenu Québec: Basic rules for applying the GST/HST and QST (in French)
- Revenu Québec: Price reductions (calculation example) (in French)
- Revenu Québec: Special rules for small suppliers (in French)
- Revenu Québec: Small suppliers (voluntary registration)
- Revenu Québec: When the GST/HST and QST must be collected (in French)
- Revenu Québec: Preparing invoices (in French)
- Revenu Québec: Checking the validity of a QST registration number (in French)
- Revenu Québec: ITCs and ITRs, operating expenses (in French)
Last checked: October 13, 2026. Rates, thresholds and invoicing requirements may change: confirm them on revenuquebec.ca and canada.ca before relying on them.
This is not legal or tax advice. This content is for information only; confirm your situation with Revenu Québec, the Canada Revenue Agency or your accountant.
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