Phone Number Formats by Country: A Complete Guide

Phone number formats vary dramatically across the world. Understanding these differences is essential for developers building international apps, QA engineers testing global phone validation, and anyone who needs to generate realistic numbers for different regions.

International Phone Number Standards

The E.164 format is the International Telecommunication Union standard:

• Starts with a + (plus sign)
• Followed by the country code (1–3 digits)
• Then the national number (area code + subscriber number)
• Maximum total length: 15 digits

Country-by-Country Format Reference

Key Differences to Know

Trunk Prefixes

Many countries use a trunk prefix (usually 0) before the area code when dialing locally. This prefix is dropped when dialing internationally. For example, a UK mobile 07911 123456 becomes +44 7911 123456 internationally.

Mobile vs. Landline Ranges

In many countries, specific digit ranges indicate mobile vs. landline. In the UK, 07xxx numbers are always mobile. In India, 6–9 starting numbers are mobile while 011, 022 etc. are landlines.

Toll-Free Formats

Toll-free numbers also vary: 800/844/855/866/877/888 in the US, 0800/0808 in the UK, 1800 in India and Australia.