Validate a QST Registration Number
You can use this service to validate a business’s QST registration number.
You can also use this service to validate the QST registration number of a supplier outside Québec. Effective January 1, 2019, certain suppliers outside Québec must register for the QST and collect the tax on certain taxable supplies they make in Québec.
To check whether a GST/HST registration number is valid, use the GST/HST registry online service available on the Government of Canada website.