Phone Number Regex Python Validator

What is Phone Number Regex in Python?

Phone number regex in Python allows you to validate if a string matches expected phone number formats—whether local, international, or formatted for readability.

In Python, this is typically done using the re module with a regular expression (regex) pattern that checks for digits, optional country codes, separators (like -,  , or ()), and valid lengths.

When to Use It?

• User signup forms to ensure phone inputs are correct

• APIs that process contact data

• CRM systems to clean and validate mobile entries

• SMS/Call systems to avoid message failure due to incorrect formats

Common Regex Patterns for Phone Numbers

1. Basic digits only (10-digit US-style number):

   ^\d{10}$

   Matches 9876543210

   
   

2. With country code (e.g., +91 for India):

   ^\+\d{1,3}\d{7,14}$

   Matches +919876543210

   
   

3. Formatted with spaces or hyphens:

   ^\+?\d{1,3}[-\s]?\(?\d{3}\)?[-\s]?\d{3}[-\s]?\d{4}$

   Matches +1 800-555-1234 or (800) 555-1234

How to Validate Phone Numbers Using Regex in Python

Here’s a complete example using the re module:

import re

def is_valid_phone(phone):
    # Allows optional country code, spaces, dashes, parentheses
    pattern = re.compile(r'^\+?\d{1,3}?[-\s]?\(?\d{2,4}\)?[-\s]?\d{3,4}[-\s]?\d{4}$')
    return pattern.match(phone) is not None

# Test cases
print(is_valid_phone("+91 98765 43210"))      # True
print(is_valid_phone("(022) 123-4567"))       # True
print(is_valid_phone("9876543210"))           # True
print(is_valid_phone("12345"))                # False

Combine with These Tools

• Email Regex Python Validator – Validate email input alongside phone data.

• IP Address Regex Python Validator – Check IP fields during signup.

• Password Regex Python Validator – Enforce strong password rules for account security.

• UUID Regex Python Validator – Validate unique user/session IDs along with phone numbers.

Pro Tips

• Always normalize phone numbers after validation for storage (e.g., remove hyphens or spaces).

• If dealing with international users, prefer patterns that support optional + and varying lengths.

• Avoid assuming a fixed length; different countries have different standards (e.g., UK, India, US).

• Use re.fullmatch() instead of re.match() if you want to strictly match the entire string.

• For UI, consider pairing regex validation with dropdowns for country codes to improve accuracy.

Use Cases

• Validating user input in Django or Flask forms

• Filtering bulk contact data in ETL pipelines

• Verifying phone numbers before sending SMS alerts

• Adding regex constraints in Python-based data validators