Canada BN Validator
Online validator for Canadian Business Number (BN9) and Program Accounts (BN15) according to CRA regulations.
How does Canadian BN validation work?
The Business Number (BN) is the primary business identifier managed by the Canada Revenue Agency (CRA). This tool validates both the 9-digit BN9 root and the 15-character BN15 program accounts.
Validation verifies that the 9-digit root adheres strictly to the Luhn checksum (Modulo 10) and that the 2-letter program code is an official CRA designation (RC, RP, RT, RZ, RM, RR).
Check Digit Calculation Algorithm (Luhn / Mod 10)
The check digit of the BN9 root is verified using the standard Luhn algorithm with alternating weights of 1 and 2:
Sum = Σ dᵢ × (if i even: 2, if i odd: 1) [with two-digit reduction]; Checksum = (10 - (Sum mod 10)) mod 10
- Extract the first 8 digits of the Canadian business number root.
- Multiply the digits alternately by 1 and 2 from left to right (weights 1, 2, 1, 2, 1, 2, 1, 2).
- If any product is 10 or greater, sum the individual digits of that product (e.g. 7 × 2 = 14 → 1 + 4 = 5).
- Sum all resulting values together.
- The check digit is the amount required to round the sum up to the nearest multiple of 10.