UK NHS Number Regex for Python

What this pattern does

This page provides a well-structured, multi-part regular expression for matching uk nhs number, ported and verified for Python. Identity and credential patterns need both correctness and safety, since they're frequent targets for adversarial input. The snippet below is ready to drop into your Python project — whether you're validating in a Django view, a FastAPI endpoint, or a standalone data processing script.

Python Implementation

# UK NHS Number
# ReDoS-safe | RegexVault — Identity & PII > Health Identifiers

import re

uk_nhs_number_pattern = re.compile(r'^([0-9]{3})[\s-]?([0-9]{3})[\s-]?([0-9]{4})$')

def validate_uk_nhs_number(value: str) -> bool:
    return bool(uk_nhs_number_pattern.fullmatch(value))

# Example
print(validate_uk_nhs_number("943 476 5919"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Identity & PII > Health Identifiers category and carries a ReDoS-safe certification. That matters for Python developers because particularly important in Python web servers where CPU-bound regex operations can stall concurrent request handling. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

The NHS number is 10 digits. The 10th digit is a check digit using a modulus 11 algorithm (weights 10-2). If the weighted sum's remainder is 0, the check digit is 0; if it's 1, the number is invalid; otherwise check digit = 11 - remainder.