New Zealand Postcode Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching new zealand postcode, ported and verified for Python. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. 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

# New Zealand Postcode
# ReDoS-safe | RegexVault — Localization > Postal Codes

import re

new_zealand_postcode_pattern = re.compile(r'^([0-9]{4})$')

def validate_new_zealand_postcode(value: str) -> bool:
    return bool(new_zealand_postcode_pattern.fullmatch(value))

# Example
print(validate_new_zealand_postcode("0110"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Localization > Postal Codes 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

New Zealand postcode ranges: 0100-0999 (Northland), 1010-1072 (Auckland central), 4410-4499 (Taupo), 6011-6099 (Wellington), 8011-8142 (Christchurch), 9016-9999 (Dunedin/Invercargill/Otago). Introduced 2006.