Thai Postal Code Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching thai postal code, 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

# Thai Postal Code
# ReDoS-safe | RegexVault — Localization > Postal Codes

import re

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

def validate_thai_postal_code(value: str) -> bool:
    return bool(thai_postal_code_pattern.fullmatch(value))

# Example
print(validate_thai_postal_code("10110"))  # 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

Thai postal codes: 10xxx (Bangkok), 20xxx-27xxx (Eastern region), 30xxx-39xxx (Northeast), 40xxx-49xxx (North/Northeast), 50xxx-58xxx (North), 60xxx-67xxx (Lower North), 70xxx-77xxx (West), 80xxx-86xxx (South). Thailand Post manages the database.