The Canadian business number

The format

A Canadian tax number on an invoice is written in two halves:

• 123456789The business number (BN): nine digits, one per business, whatever it does and wherever it does it.
• RT0001The program account: two letters saying which tax, four digits saying which account of that kind.

The letters are worth knowing, because only one of them is the sales tax:

• RTGST/HST — the one that appears on an invoice.
• RPPayroll deductions.
• RCCorporate income tax.
• RMImport/export.

The ninth digit is a Luhn check — the same rule a bank card number follows — so a mistyped business number can be caught before any network call, like a French key or a Polish NIP.

Vatlas accepts either spelling. CA100768779RT0001 and CA100768779 are the same company, and the program account is dropped before the number is looked up, so both return the same record.

A business number is not a GST registration

This is the Canadian trap, and it has no European equivalent. A business can hold a business number and not be registered for GST/HST at all: registration is only compulsory above 30,000 CAD of taxable supplies, and a smaller supplier may register voluntarily or not at all. So the nine digits identify the business; whether an RT account exists behind them is a separate fact.

Quebec adds a second number. The provincial sales tax there — the QST — is administered by Revenu Québec, and a Quebec supplier quotes a QST number of its own alongside the federal one. They are two registrations, with two numbers, and neither is derivable from the other.

Finding the company behind the number

Corporations Canada

Corporations Canada — the federal registrar — publishes its whole register as open data: one archive, no account, no key, under the Open Government Licence. It holds 1.59 million corporations, of which 1.47 million carry a business number, and that number is what makes the file reachable by what is written on an invoice.

It is what Vatlas imports, so a Canadian lookup is a database read rather than a call to Ottawa.

What the register does and does not contain

It contains the corporate name in force, the registered office, the corporation's status, the statute it exists under — the Canada Business Corporations Act, the Not-for-profit Corporations Act, the Cooperatives Act — and the whole history of each of those, dated.

What it does not contain is any corporation that is not federal. A company incorporated in Ontario, Quebec or British Columbia holds a business number like any other and is registered with its province, not with Corporations Canada, so it is absent from this file. The provincial registries publish their own numbers and cannot be keyed by a business number, which is why nothing fills that gap here.

The CRA's own registry

The CRA runs a GST/HST Registry, and it answers a different question from the one asked here: you supply the first nine digits, the exact legal name and a transaction date, and it confirms whether that account was registered on that day. It confirms; it does not tell you who the number belongs to, and it has no API.

Canada-specific pitfalls

• A business number is not proof of GST registration. Below 30,000 CAD a year, registering is optional.
• Federal corporations only. Provincially incorporated companies are in their province's register, not in this one.
• Quebec suppliers have two numbers. The QST number is Revenu Québec's and is not built from the business number.
• The program account is not the company. RT0001, RP0001 and RC0001 are three accounts of one business.
• "Intent to dissolve" is still active. A corporation with a dissolution pending exists and still charges tax.

One API, one response shape

Vatlas turns a business tax number into a company record: legal name, national identifier, legal form, status and address. Canada — the same call and the same response as for every other country covered.

curl "https://api.vatlas.dev/v1/lookup/CA100623040" \
  -H "Authorization: Bearer $VATLAS_KEY"

Response:

200 OK

{
  "data": {
    "vatNumber": "CA100623040",
    "countryCode": "CA",
    "nationalNumber": "100623040",
    "nationalId": "328341",
    "name": "BRAND FELT OF CANADA LIMITED",
    "legalForm": "Canada Business Corporations Act",
    "status": "active",
    "address": {
      "line1": "2559  WHARTON GLEN AVENUE",
      "line2": null,
      "postalCode": "L4X 2A8",
      "city": "MISSISSAUGA, ON",
      "country": "CA"
    }
  },
  "meta": {
    "source": "CORPCAN",
    "sourceDate": "2026-09-09",
    "sourceSince": "2026-09-09",
    "sourceUpdatedAt": "2019-05-29T10:30:47.000Z"
  }
}

meta.source names the register that answered (SIRENE, ARES, VIES…) and meta.sourceDate the day it said so: the publication date of the file for a register we import, the day of the call for one we query live. The shape of the response never changes from one country to the next.

Get a free key Read the documentation

Business numbers in other countries

• Australia
• Brazil
• Japan
• France
• Peru
• All countries

Last updated 15 September 2026.