Phone Number Formatter

Convert any phone number into E.164, international, national, and RFC 3966 formats instantly. Get the exact format required by your SMS API or CRM.

Format Quick Reference

FormatExample (US)Use case
E.164+14155550123SMS APIs, telephony, databases
International+1 415 555 0123User-facing display, international calls
National(415) 555-0123Local UI display
RFC 3966tel:+14155550123HTML tel: links, SIP, CRM
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Frequently Asked Questions

What is E.164 format?
E.164 is the international standard (ITU-T) for phone numbers. Format: + country_code subscriber_number, no spaces. Example: +14155550123. Required by most SMS APIs (Twilio, AWS SNS, etc.).
What is the difference between international and national format?
International format includes the + country code and is used globally. National format omits the country code and uses local conventions (e.g. (415) 555-0123 for US, 07911 123456 for UK). Use international for APIs; national for UI display.
What is RFC 3966 format?
RFC 3966 is the URI format for phone numbers, used in HTML href="tel:" links and SIP. Format: tel:+14155550123. Some CRM and VOIP systems require this format.
Why does the formatter need a + country code?
Without a country code, the same national number is ambiguous — 07911 123456 could be UK, and the formatter cannot correctly apply national formatting rules without knowing the country.

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