New Zealand IRD Validator
Online validator for New Zealand Inland Revenue Department (IRD Number) with two-stage Modulo 11 verification.
About the Inland Revenue Department (IRD Number)
New Zealand tax identification number.
Supports 8 or 9 digits with or without hyphens.
New Zealand IRD Anatomy & Structure
The IRD Number is issued in 8-digit or 9-digit format (NN-NNN-NNN or NNN-NNN-NNN):
| Position | Field | Length | Rule & Meaning | Example |
|---|---|---|---|---|
| 1 to 7/8 | Base Number | 7 or 8 digits | Sequential number issued by Inland Revenue | 4909185 |
| End | Check Digit | 1 digit | Integrity check digit calculated via two-stage Modulo 11 | 0 |
Official Algorithm (Two-Stage Modulo 11 — Inland Revenue)
Official verification method from New Zealand Inland Revenue Department:
Stage 1: W1 = [3, 2, 7, 6, 5, 4, 3, 2]; if 11 - (S1 mod 11) === 10 -> Stage 2: W2 = [7, 4, 3, 2, 5, 2, 7, 6].
- 1. Pad base number to 8 digits.
- 2. Apply Stage 1 weights and check remainder.
- 3. If check digit is 10, proceed to Stage 2.
- 4. Verify match against the last digit.