Dutch BSN Validator (Netherlands)
Validate Dutch Burgerservicenummer (BSN) in real time via the 11-proef algorithm.
Dutch BSN Validation
Validation checks the 9 digits and applies the test of 11 to verify if the weighted sum is divisible by 11.
Essential for e-commerce, taxation, and healthcare systems operating in the Netherlands.
Anatomy & Structure of Dutch BSN
The Burgerservicenummer consists of 9 decimal digits regulated by RvIG:
| Position | Field | Length | Meaning & Rule | Example |
|---|---|---|---|---|
| 1 to 8 | Sequential Base | 8 digits | Random sequential number issued by Dutch civil registry (RvIG/BRP) | 12345678 |
| 9 | Check Digit | 1 digit | Security digit validated with negative multiplier (-1) in 11-proef | 2 |
BSN Calculation & Validation Algorithm (11-proef)
BSN validation uses a specific variant of the test of 11 with negative weight:
(d1×9 + d2×8 + d3×7 + d4×6 + d5×5 + d6×4 + d7×3 + d8×2 - d9×1) mod 11 = 0
- 1. Sanitize input and pad with leading zero if 8 digits to reach 9 positions.
- 2. Multiply each of the first 8 digits by descending weights from 9 down to 2.
- 3. Subtract the 9th digit (multiplier -1) from the accumulated sum.
- 4. Check if the final result is divisible by 11 (remainder zero).
- 5. Reject numbers consisting purely of zeros (000000000).