Nine-digit CRA identifier that anchors payroll program accounts and employer-side payroll registration.
A business number, often shortened to BN, is the unique 9-digit CRA identifier for a business.
In payroll context, it matters because the employer’s payroll account, remittances, and filings all sit under that business identity. It is not an employee pay-stub term. It is part of the employer’s payroll setup.
Business number matters because it affects:
Payroll can be calculated correctly and still be operationally incomplete if the employer-side registration structure is wrong.
The business number is the broader CRA identifier. A payroll deductions account is then built by adding a program code and reference number to that BN. In practice, payroll staff or bookkeepers may encounter the BN when:
You can only have one BN for the business, but that BN can have one or more program accounts under it. That is why the BN is the foundation of the employer’s CRA payroll identity, not the payroll account by itself.
| CRA identifier layer | Example format | What it identifies | Why payroll readers should keep it separate |
|---|---|---|---|
| Business number | 123456789 | The business’s core CRA identity | It is the base identifier, not the full payroll account |
| Payroll program account | 123456789 RP 0001 | One payroll deductions account under the BN | This is the account payroll uses for remittance and filing |
| Another CRA program account | 123456789 RT 0001 | A different CRA program such as GST/HST | The same BN can support several programs without changing the BN itself |
| Payroll task | Why the BN appears | Why it matters |
|---|---|---|
| Opening a payroll account | CRA needs the business identity first | You cannot have an RP payroll account without the underlying BN |
| Setting up payroll software or service access | The employer account must be tied to the right CRA identity | Wrong employer identifiers create filing and reconciliation problems |
| Matching CRA correspondence | Letters and notices may refer to the BN and the full program account | Payroll staff need to know which part is the base identifier and which part is the program account |
| Expanding to more than one payroll account | The BN stays the same while the reference number changes | This helps explain why RP 0001 and RP 0002 can both belong to one business |
An employer has the BN 123456789. Its main payroll account may then appear as 123456789 RP 0001. If the employer later needs a second payroll account, the BN stays the same and only the final reference number changes.
RP and a 4-digit reference number.The core BN concept is stable, but exact registration workflow and the number of payroll accounts under the BN can vary by employer structure and CRA setup.