Check a GST/HST, QST or PST number
A supplier's registration number is part of what supports your input tax credit. This checks the shape of one before you file on it.
How this is calculated
To claim an input tax credit you need evidence, and for invoices over a threshold that evidence includes the supplier’s registration number. A number that is malformed is a signal worth catching before the return goes in: sometimes it is a typo, and occasionally it means the supplier is charging tax they are not registered to collect.
Canada issues several different kinds, and they look different:
- GST/HST is a business number followed by an RT program identifier and a four-digit reference.
- QST is a ten-digit Quebec number followed by TQ and a reference: administered by Revenu Québec, not the CRA.
- BC PST, Saskatchewan PST and Manitoba RST each run their own provincial format.
This checks format only. Whether a number is genuinely registered and active is a live lookup with the administering authority, which no static page can answer: and a tool that implied otherwise would be worse than none at all for someone relying on it.
Where these figures come from
- Canada Revenue Agency — When to register for and start charging the GST/HST , checked August 6, 2026
This tool gives an estimate from published rules and rates. It is not accounting, tax or legal advice, and it does not account for every situation: check the source above, or ask your accountant, before you act on it. Nothing you enter is stored or sent anywhere.