E.164 International Phone Number Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching e.164 international 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

# E.164 International Phone Number
# ReDoS-safe | RegexVault — Localization > Phone Numbers

import re

e164_international_phone_number_pattern = re.compile(r'^\+[1-9][0-9]{6,14}$')

def validate_e164_international_phone_number(value: str) -> bool:
    return bool(e164_international_phone_number_pattern.fullmatch(value))

# Example
print(validate_e164_international_phone_number("+6591234567"))  # 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

E.164 is the global standard for phone numbers in international telephony. Maximum 15 digits (country code + subscriber). No spaces, dashes, or parentheses. Always store phone numbers in E.164 format.