The New Zealand Business Number (NZBN) is a unique 13-digit identifier given to every business in New Zealand. It is technically a GS1 Global Location Number, which is why it follows the same EAN-13 check-digit rules used on retail barcodes.

How is the NZBN check digit calculated?

Take the first 12 digits, weight them alternately 1 and 3 starting from the left, sum the products, and the check digit is 10 minus the last digit of that sum, modulo 10. It must equal the 13th digit of the NZBN.

Why do NZBNs start with 942 or 943?

Those are the GS1 New Zealand company prefixes. As GS1 Global Location Numbers, NZBNs typically begin with the 94 country prefix assigned to GS1 New Zealand, though the validator checks the math, not the prefix.

Does a valid check digit mean the business is registered?

No. A valid check digit only confirms the number is internally well-formed. It does not confirm the business is currently listed on the NZBN Register or that it is active — use the official register to verify that.

Is my data sent anywhere?

No. The check-digit calculation runs entirely in your browser. The number you enter never leaves your device and no register lookup is performed.

New Zealand NZBN Validator

The New Zealand Business Number (NZBN) is a unique 13-digit identifier issued to every business operating in New Zealand. Behind the scenes it is a GS1 Global Location Number, so it carries the same modulus-10 check digit used on EAN-13 retail barcodes. This free validator runs that exact check in your browser — handy for procurement teams, Inland Revenue (IR) filings, and developers integrating the NZBN Register.

How it works

The GS1 modulus-10 check works on the 13-digit number:

Strip any spaces, leaving 13 digits.
Take the first 12 digits as the data.
Weight them alternately 1, 3, 1, 3, ... starting from the leftmost digit.
Sum all the weighted products.
The check digit is (10 - (sum mod 10)) mod 10 — it must equal the 13th digit.

The tool shows the weighted sum, the expected check digit and the actual 13th digit, so you can see precisely why a number passes or fails.

Example and notes

NZBNs typically begin with the GS1 New Zealand prefix 94. The validator does not assume a particular prefix — it simply applies the mod-10 math to whatever 13 digits you enter and reports whether the check digit is consistent.

A passing check digit means the number could not contain a single mistyped or transposed digit, but it does not confirm the business is registered or active. Only the official NZBN Register can confirm that. Everything here runs locally, so no number is transmitted anywhere.