NHI Number Format Changes

The NHI has enough numbers at the current rates of allocation to assign to people until 2025. The Ministry is working with the sector to introduce a change to the NHI number format to extend the range of NHI numbers available.

This involves checking and (where necessary) upgrading the health sector’s IT systems which record NHI numbers to accept a new format. This work is underway now to allow time for these checks and any upgrades to take place.

NHI numbers will start to be issued in the new format from 1 October 2025.

At the moment, NHI numbers are a unique 7-character number in the format AAANNNC (3 alpha, 3 numeric and one numeric check digit). The new format will be AAANNAX (3 alpha, 2 numeric, 1 alpha and one alpha check digit). 

The first new format NHI number will be issued from 1 October 2025.

NHI numbers are currently issued sequentially on the first six characters, e.g ZAA0067, ZAA0075, ZAA0083, [...] ZAB0003, ZAB0011, ZAB0020, ZAB0038, and so on.

This will change with the new format NHI numbers. NHI numbers will be issued in sequential order of the first letter, starting with A’s, and then a randomised allocation of the next 5 characters, with the last character an alpha check digit. e.g. ACA31FM, ASE37QK, ARE62RS, […] BGJ06AS, BGA44DT, BWT41BY.

Details of the change can be found in the HISO 10046:2023 Consumer Identity Standard.

Sector systems that use NHI numbers will need to make sure they can use both the current NHI numbering format and the new format which will come into effect 1 October 2025.

Some systems may need to be upgraded, and it’s important that sufficient time is allowed for this work. We recommend that systems are ready to accommodate the new format well ahead of the planned cutover date of 1 October 2025.

Changing to the alpha/numeric/alpha format and retaining the existing 7 character length is considered the option that will have the least impact on the sector, and is unlikely to require a change in most databases.

The costs of upgrading any systems is expected to be managed by software vendors and software providers. The NHI represents a fundamental health system standard.

If you would like to know more about what the NHI number format changes might mean for you, please contact integration@health.govt.nz