Locales

fhir-test-data supports 14 locale codes. Each locale provides country-specific name pools, address formats, and identifier systems with check-digit validation.

Supported locales

Country	Code	Patient identifiers	Algorithm	Practitioner identifiers
United States	us	SSN, MRN	Format validation	NPI (Luhn)
United Kingdom	uk	NHS Number	Modulus 11	GMC Number, GMP Number
Australia	au	IHI, Medicare	Luhn	HPI-I (Luhn)
Canada	ca	Ontario HCN	Format validation	—
Germany	de	KVID-10	Format validation	LANR (Modulus 10)
France	fr	NIR	Modulus 97	RPPS (Luhn)
Netherlands	nl	BSN	11-proef	UZI Number
India	in	Aadhaar, ABHA	Verhoeff	—
Japan	jp	—	—	—
South Korea	kr	RRN (gender-aware)	—	—
Singapore	sg	—	—	—
Brazil	br	—	—	—
Mexico	mx	—	—	—
South Africa	za	—	—	—

Selecting a locale

All builders accept a .locale(code) method:

import {
  createPatientBuilder,
  createPractitionerBuilder,
  createOrganizationBuilder,
} from "fhir-test-data";

const [ukPatient] = createPatientBuilder().locale("uk").seed(1).build();
const [nlPatient] = createPatientBuilder().locale("nl").seed(1).build();
const [dePractitioner] = createPractitionerBuilder().locale("de").seed(1).build();

The locale affects:

• Identifier systems — which identifier types are generated, with which system URLs
• Name pools — given names, family names, and title prefixes appropriate to the country
• Address format — street patterns, city names, postal code format, and country code
• Communication language — the Patient.communication entry uses the locale's BCP 47 tag

Identifier systems

United Kingdom (uk)

Patient: NHS Number

The NHS Number is a 10-digit identifier validated with Modulus 11. The check digit (the last digit) is computed from the first 9 digits with weights 10–2. A result of 10 means the number is invalid and must be regenerated — this is handled automatically.

System: https://fhir.nhs.uk/Id/nhs-number
Format: DDDD DDDDDD (10 digits)

Practitioner: GMC Number (General Medical Council) or GMP Number (GP contract).

Australia (au)

Patient: IHI (Individual Healthcare Identifier) and Medicare number

Both are Luhn-validated. The IHI is a 16-digit number issued by Services Australia. The Medicare number is 10 digits with a check character.

IHI system:      http://ns.electronichealth.net.au/id/hi/ihi/1.0
Medicare system: http://ns.electronichealth.net.au/id/medicare-number

Practitioner: HPI-I (Healthcare Provider Identifier — Individual), Luhn-validated.

Netherlands (nl)

Patient: BSN (Burgerservicenummer)

The BSN is a 9-digit number validated with 11-proef (a Modulus 11 variant). Weights 9, 8, 7, 6, 5, 4, 3, 2, −1 are applied to digits 1–9. The weighted sum must be divisible by 11.

System: http://fhir.nl/fhir/NamingSystem/bsn
Format: DDDDDDDDD (9 digits)

Practitioner: UZI Number (healthcare professional registry).

France (fr)

Patient: NIR (Numéro d'Inscription au Répertoire — social security number)

The NIR is a 15-digit number. The check key is 97 - (first 13 digits mod 97), computed with BigInt to avoid JavaScript floating-point loss.

System: http://terminology.hl7.org/NamingSystem/fr-nia
Format: D DDDDDD DDDDDDD DD (15 digits + 2-digit key)

Practitioner: RPPS (Répertoire Partagé des Professionnels de Santé), Luhn-validated.

India (in)

Patient: Aadhaar and ABHA (Ayushman Bharat Health Account)

The Aadhaar number is 12 digits validated with the Verhoeff algorithm — a dihedral group D5 algorithm that detects all single-digit errors and all adjacent transposition errors.

Aadhaar system: https://uidai.gov.in
Format: DDDD DDDD DDDD (12 digits)

Germany (de)

Patient: KVID-10 (Krankenversichertennummer)

Practitioner: LANR (Lebenslange Arztnummer), validated with Modulus 10 on the first 6 digits.

LANR system: https://fhir.de/NamingSystem/lanr
Format: DDDDDDDDD (9 digits)

South Korea (kr)

Patient: RRN (Resident Registration Number)

The RRN is a 13-digit number. The 7th digit encodes gender and century of birth: 1/2 for 1900s, 3/4 for 2000s, 5/6 for foreign nationals born in 1900s/2000s.

Name and address generation

Each locale includes pools of:

• Given names — 30+ names per gender (male, female), drawn from the locale's cultural background
• Family names — 40+ surnames appropriate to the country
• Prefixes — locale-appropriate professional or courtesy titles

Address generation uses realistic street name patterns, actual city names, and correctly formatted postal codes for each country.

All names and addresses are drawn deterministically from the seed — the same seed always produces the same name for the same locale.