Hong Kong HKID Number Regex for Python

What this pattern does

This page provides a well-structured, multi-part regular expression for matching hong kong hkid 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

# Hong Kong HKID Number
# ReDoS-safe | RegexVault — Identity & PII > National Identity Numbers

import re

hong_kong_hkid_number_pattern = re.compile(r'^([A-Z]{1,2})([0-9]{6})\(([0-9A])\)$')

def validate_hong_kong_hkid_number(value: str) -> bool:
    return bool(hong_kong_hkid_number_pattern.fullmatch(value))

# Example
print(validate_hong_kong_hkid_number("A123456(7)"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Identity & PII > National Identity Numbers 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

Structure: 1-2 uppercase letters + 6 digits + check character (0-9 or A) in parentheses. A single letter prefix is padded with a space for checksum calculation. The check character is computed via weighted sum mod 11.