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Reference

Phone number formats by country

Digit counts, mobile and landline prefixes, trunk-prefix rules, and E.164 examples: the reference you actually need when you are writing validation or cleaning an import file.

Reviewed by Sujan ThapaliyaLast updated

What is the correct international phone number format?

E.164: a leading +, the country calling code, then the national number with no spaces, dashes, or brackets, and at most 15 digits in total. Any national trunk prefix (the leading 0 in most of Europe, Asia, and Africa) is removed. It is the only format that is unambiguous everywhere, and the only sensible way to store a number.
The structure of a phone number under ITU-T E.164: a country calling code, then a national destination code, then the subscriber number, to a maximum of fifteen digits after the plus sign. The diagram contrasts the national format people write by hand with the E.164 form a database should store.
National formats are for people; E.164 is for storage, APIs, and caller ID.

At a glance

Which country formats get looked up most?

Mobile examples, written the way they appear domestically and in E.164.

CountryCodeMobile patternE.164 example
United States+1+1 (NPA) NXX-XXXX (same format as landline)+12125550187
United Kingdom+44+44 7XXX XXXXXX+447700900123
Germany+49+49 1XX XXXXXXX+4915112345678
France+33+33 [67] XX XX XX XX+33612345678
India+91+91 XXXXX XXXXX+919876543210
Japan+81+81 [789]0 XXXX XXXX+819012345678
South Korea+82+82 10 XXXX XXXX+821012345678
Australia+61+61 4XX XXX XXX+61491570006
Brazil+55+55 XX 9XXXX XXXX+5511912345678
Mexico+52+52 XX XXXX XXXX+525587654321

Practice

Three rules that prevent most phone-data bugs

  1. Store E.164, display anything. One canonical value in the database, formatted for humans at render time. Storing the pretty version is how the same customer ends up in your CRM four times.
  2. Never store a phone number as an integer. Leading zeros vanish, the plus sign vanishes, and no phone number has ever been usefully added to another.
  3. Validate format, not existence. Format checks belong on the form; whether a number is live is a carrier lookup, and it is the only check that catches disconnected lines before you waste a dial on them.

Frequently asked questions

What is E.164 format?
E.164 is the ITU standard for international phone numbers: a leading plus sign, the country calling code, then the national number, with no spaces or punctuation and no more than 15 digits in total. +14155550123 and +442079460123 are both E.164.
How should I store phone numbers in a database?
In E.164, as a string, always. Never as a number: leading zeros and plus signs are lost, and no phone number is ever used arithmetically. Format for display at render time; keep one canonical value stored so deduplication and lookups actually work.
What is the international format for a US phone number?
+1 followed by the ten-digit number: (415) 555-0123 becomes +14155550123. The US has no trunk prefix to remove; the 1 sometimes dialled before a long-distance call is the country code itself.
How strictly should I validate a phone number on a form?
Loosely. Accept spaces, dashes, brackets, and a leading trunk 0, then normalise. Check length and prefix against the country, and stop there. Rejecting a real customer because they wrote their number the way they always write it is far more expensive than storing one odd row.
Can I tell whether a number is a mobile from its format?
In many countries, yes: the UK's 07, India's 6–9 opening digit, Australia's 04. In North America you cannot: mobile and fixed lines share the same format and only a carrier lookup distinguishes them.

Sources

  1. ITU-T Recommendation E.164 — The international public telecommunication numbering planInternational Telecommunication UnionThe international number format, the 15-digit maximum, and how country codes and national numbers compose.
  2. ITU-T International Numbering ResourcesInternational Telecommunication UnionThe assignment of country calling codes and the published national numbering plans they belong to.

Let the platform handle the formatting

Every imported number is normalised to E.164, matched to its country, screened against your suppression lists, and displayed correctly, before any of it reaches a dialer.

  • Automatic normalisation
  • DNC screening on import
  • 100+ countries