US/Canada Phone Number (NANP) Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching us/canada phone number (nanp), 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

# US/Canada Phone Number (NANP)
# ReDoS-safe | RegexVault — Localization > Phone Numbers

import re

uscanada_phone_number_nanp_pattern = re.compile(r'^(?:\+1[\s.-]?)?(?:\(([2-9][0-9]{2})\)|([2-9][0-9]{2}))[\s.-]?([2-9][0-9]{2})[\s.-]?([0-9]{4})$')

def validate_uscanada_phone_number_nanp(value: str) -> bool:
    return bool(uscanada_phone_number_nanp_pattern.fullmatch(value))

# Example
print(validate_uscanada_phone_number_nanp("+1 212-555-0100"))  # 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

NANP area codes and exchange codes cannot start with 0 or 1. Capture groups: 1/2=area code, 3=exchange, 4=subscriber. 555-0100 through 555-0199 are reserved for fiction. Toll-free: 800, 888, 877, 866, 855, 844, 833.