An illustrative GST/HST account number is 123456789 RT 0001. It combines a nine-digit Business Number (BN), the RT GST/HST program identifier and a four-digit reference number. The CRA uses the same account format for GST and HST; the letters do not change with the provincial rate. CRA program-account guidance gives this format and example.
GST/HST number format at a glance
| Part | Example | Meaning |
|---|---|---|
| Business Number | 123456789 |
The business’s nine-digit CRA identifier |
| Program identifier | RT |
GST/HST program account |
| Reference number | 0001 |
A four-digit reference for the program account |
| Full account | 123456789 RT 0001 |
The 15-character GST/HST account number |
123456789RT0001 is the same illustrative sequence when written without spaces. The example is not a real supplier number and should not be used on an invoice.
RT0001 versus RC0001
The two letters identify the CRA program. RT is the GST/HST program account. RC is corporate income tax; RP is payroll deductions; RZ is information returns. A 9-digit BN can be shared across a business’s CRA programs, but the program identifier and reference identify the account used for the particular obligation.
How to verify a number before claiming an ITC
Do not rely on the visual format alone. The CRA’s free GST/HST Registry lets you confirm that a supplier charging GST/HST is registered. You need the supplier’s name, transaction date and the first nine digits of the GST/HST account number. The CRA specifically says to enter only those first nine digits and not the letters.
The registry result should match the transaction date. The CRA recommends retaining the Search Details screen to support input tax credit claims. If a supplier does not provide an account number, ask the supplier or contact CRA Business Enquiries before relying on the tax charge.
For an invoice layout, see how to show GST/HST on an invoice. The CRA says suppliers must include the GST/HST account number on receipts, invoices, contracts or other business papers for taxable supplies of $100 or more.
GST/HST is federal; other tax IDs can be separate
The RT account is the federal GST/HST account. A province can have separate sales-tax registration and verification rules, so a provincial number is not a substitute for a valid federal RT account. For tax-rate calculations, use the GST/HST calculator and confirm the province of supply.