A function to check strings against the New Zealand Ministry of Health NHI Validation Routine. Supports the old and new NHI number formats specified in HISO 10046:2023.

Add the following to your PklProject:

dependencies {
  ["nhi"] { 
    uri = "package://pkg.pkl-lang.org/github.com/James-Ansley/pkl-nhi/[email protected]"
  }
}

Use the nhi.isValid function:

import "@nhi/nhi.pkl"

typealias Nhi = String(nhi.isValid(this))

myOtherValidNhi: Nhi = "ZAC5361" // works
myOtherInvalidNhi: Nhi = "ZZZ0044"  // fails

Checks are case-insensitive.

Note: This does not check that the NHI number has been assigned to a person, it merely checks the NHI is consistent with the HISO 10046:2023 standard.

NHI numbers that begin with Z are reserved for testing. If you wish to exclude these values, you will need to manually check for a Z prefix:

import "@nhi/nhi.pkl"

typealias Nhi = String(nhi.isValid(this), !startsWith("Z"), !startsWith("z"))

myNhi1: Nhi = "ABC12AY" // works
myNhi2: Nhi = "ZAC5361"  // fails

Note: This check does not mean that the NHI number has been assigned to a person, it just means that the NHI value is not reserved for testing.

• https://www.tewhatuora.govt.nz/publications/hiso-100462023-consumer-health-identity-standard/
• https://www.tewhatuora.govt.nz/our-health-system/digital-health/health-identity/national-health-index/information-for-health-it-vendors-and-developers