Austrian Postcode (PLZ) Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching austrian postcode (plz), 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

# Austrian Postcode (PLZ)
# ReDoS-safe | RegexVault — Localization > Postal Codes

import re

austrian_postcode_plz_pattern = re.compile(r'^([1-9][0-9]{3})$')

def validate_austrian_postcode_plz(value: str) -> bool:
    return bool(austrian_postcode_plz_pattern.fullmatch(value))

# Example
print(validate_austrian_postcode_plz("1010"))  # 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

Austrian PLZ ranges: 1000-1999 (Vienna), 2000-2999 (Lower Austria east), 3000-3999 (Lower Austria west), 4000-4999 (Upper Austria), 5000-5999 (Salzburg). Starts at 1000 — no leading zeros.