Canada doesn't have one sales tax — it has three, layered, with rates varying by province and a compound calculation in Quebec. The 5% federal GST applies everywhere, but in Ontario and the Atlantic provinces it's absorbed into a harmonised HST. In BC, Saskatchewan and Manitoba, the federal GST stays separate from a provincial PST. In Quebec, things get really interesting: GST plus QST, and the QST is calculated on the GST-inclusive amount — a compound calculation that trips up every American invoicing tool ported north. 4invoices encapsulates this logic: you enter the customer's shipping province, the right rate appears on the invoice.
Selling across provinces with different rates
Tax rate is determined by the customer's shipping province, not your business province. A Vancouver business selling to a Toronto customer charges 13% HST (Ontario rate), not 12% (BC GST+PST). 4invoices applies the rule automatically based on the customer's shipping address. The province of supply is recorded on the invoice for future CRA audit, and the GST/HST report breaks down by province what was collected for each.
Quebec's compound calculation that breaks other software
QST at 9.975% is calculated on the GST-inclusive amount, not the subtotal. For a $100 sale: $5 GST + 9.975% on $105 = $10.47 QST, total $115.47. Many American tools imported into Canada calculate QST flat on $100 ($9.98) and under-bill by $0.49 per sale — over 10,000 invoices a year that's $4,900 missing from your QST return that Revenu Quebec will claw back with interest. 4invoices does the compound calculation that Revenu Quebec requires.
The $30,000 small-supplier threshold and tracking it
Until your worldwide taxable revenue over 4 consecutive quarters stays under $30,000, you're a small supplier and aren't required to collect GST/HST. The moment you exceed $30,000 across any rolling 4 quarters, you must register within 29 days and start collecting tax. 4invoices tracks your taxable revenue in real time and alerts at $25,000 — you get time to apply for a GST/HST number cleanly before the trigger fires.
Understanding the mechanics of Canadian taxes
The 5% federal GST is the common layer across all of Canada. The Canada Revenue Agency (CRA) collects and redistributes it. In Quebec, Revenu Quebec collects GST on behalf of CRA — which simplifies admin: one tax authority, one combined GST/QST return. Elsewhere, you file GST directly with CRA via NETFILE or form GST34.
The Atlantic provinces (New Brunswick, Nova Scotia, PEI, Newfoundland and Labrador) and Ontario harmonised their provincial tax with federal GST into HST — Harmonised Sales Tax. You file one HST amount (13% Ontario, 15% Atlantic) which CRA splits between federal and provincial. No separate provincial return.
British Columbia (PST 7%), Saskatchewan (PST 6%) and Manitoba (PST 7%) kept a separate provincial tax. You charge 5% GST plus the provincial PST, and file PST with the provincial revenue authority (each province's Ministry of Finance). Alberta, Yukon, Northwest Territories and Nunavut have no provincial sales tax — only federal 5% GST. For businesses in these jurisdictions, the simplest tax regime in Canada.
Frequently asked
I'm based in Alberta, I sell across Canada. What rate do I charge?
The customer's shipping province's rate, not yours. To an Albertan customer: 5% GST only. To an Ontario customer: 13% HST. To a Quebec customer: 5% GST + 9.975% QST (QST on GST-inclusive base). 4invoices applies the rule automatically based on the customer shipping address entered on the invoice.
I sell to a US customer. GST yes or no?
Exports outside Canada are zero-rated — you charge no GST/HST/QST. But you must retain proof of export (international shipping document, air waybill, customs certificate). 4invoices automatically flags invoices with non-Canadian shipping addresses as zero-rated and stores uploaded export documents.
What happens if I'm not GST-registered but I exceed $30,000?
You must register within 29 days of exceeding the threshold and start collecting GST/HST on sales after that date. Earlier sales remain without GST. If you don't register, the CRA can claim the GST you should have collected, plus penalties and compound interest. 4invoices alerts at $25,000 to give you time to handle registration properly.
Configure your tax matrix in 3 minutes
Free trial, no credit card. Enter your business province and your selling provinces — 4invoices applies the right GST/HST/QST rates automatically.