FIG 0.0 · REGISTRATION
When to register for taxes?
In Quebec, you have to register for GST and QST once your taxable sales pass 30 000 $ over 4 consecutive quarters. Below that threshold, registering is optional but often worth it.
Upsides of registering voluntarily
- Claim back the taxes paid on your purchases (ITC/ITR)
- A more professional image
- Required if your suppliers ask for it
Downsides
- Extra paperwork
- Periodic returns to file
- Higher prices for non-registered clients
Tip — Even below the 30 000 $ threshold, registering pays off if you have a lot of business expenses (equipment, software, supplies). You claim back the GST and QST on all your business purchases.
FIG 0.1 · 2026 RATES
Tax rates in effect in 2026
5,000%
GST (federal)
Goods and Services Tax
9,975%
QST (provincial)
Quebec Sales Tax
14,975%
Combined rate
Total of both taxes
Heads up — Since 2013, the QST is calculated on the amount BEFORE taxes, not on the amount including GST. Both taxes are calculated in parallel on the same base amount.
FIG 0.2 · DETAILS
Required details on an invoice
Every invoice in Quebec has to include this information:
1Your business name and address
2GST number (format: 123456789 RT0001)
3QST number (format: 1234567890 TQ0001)
4Client name and address
5Invoice date
6Description of the goods or services
7Amount before taxes
8GST amount
9QST amount
10Total including taxes
toncrm.io calculates GST/QST automatically on every invoiceTry it free
FIG 0.3 · CALCULATION
How to calculate GST and QST
Let's take a real example with a service at 1 000 $:
Amount before taxes1 000,00 $
GST (5%): 1 000 x 0,0550,00 $
QST (9,975%): 1 000 x 0,0997599,75 $
Total1 149,75 $
For the reverse calculation (finding the amount before taxes from the total), divide by 1,14975. Example: 1 149,75 $ / 1,14975 = 1 000 $.
Tip — Use our free GST/QST calculator to check your numbers instantly.
FIG 0.4 · REMITTANCE
Remitting taxes (returns)
The taxes you collect aren't yours — you're a middleman between your client and the government. You have to remit them periodically:
GST (federal)
Return filed with the Canada Revenue Agency (CRA). Quarterly or annual depending on your revenue.
QST (provincial)
Return filed with Revenu Québec. Usually the same frequency as the GST.
Heads up — Remitting taxes late means penalties and interest. Set a reminder in your calendar 30 days before each due date.
FIG 0.5 · MISTAKES
Common mistakes to avoid
❌ Calculating the QST on the amount including GST
✅ Both taxes are calculated on the amount BEFORE taxes
❌ Forgetting the tax numbers on the invoice
✅ Your client can't claim their ITC/ITR without your numbers
❌ Not splitting GST and QST on the invoice
✅ Both amounts have to be shown separately
❌ Charging taxes on exempt services
✅ Some services (health, education) are exempt. Double-check!
❌ Keeping the taxes you collect in your chequing account
✅ Open a separate account for taxes. It saves you nasty surprises
FIG 0.6 · TOOLS
Recommended tools
To simplify your GST/QST billing:
- GST/QST calculator — check your numbers
- Invoice generator — create compliant invoices
- GST/QST invoice template — a ready-to-use template
toncrm.io calculates GST/QST automatically on every invoiceTry it free
