UK Phone Number Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching uk phone number, 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

# UK Phone Number
# ReDoS-safe | RegexVault — Localization > Phone Numbers

import re

uk_phone_number_pattern = re.compile(r'^(?:\+44|0)(?:\s|-)?(?:[1-9][0-9]{1,4})(?:\s|-)?(?:[0-9]{3,4})(?:\s|-)?(?:[0-9]{3,4})$')

def validate_uk_phone_number(value: str) -> bool:
    return bool(uk_phone_number_pattern.fullmatch(value))

# Example
print(validate_uk_phone_number("+44 20 7946 0958"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Localization > Phone 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

UK uses a complex numbering plan. 020 = London, 0161 = Manchester, 07xxx = mobile, 0800 = freephone, 01xxx/02xxx = geographic. The (0) is sometimes shown in international format (+44 (0)20...) but not dialed.