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Regex: Phone number (E.164)

E.164 is the international format that telephone networks and SMS APIs expect: a +, the country code, then the number, at most 15 digits in all and no spaces. +14155552671 is a US number, +48123456789 a Polish one.

Open in Regex Tester The pattern and every example below are filled in.

Pattern

^\+[1-9]\d{1,14}$

How it works

^
Start of the string.
\+
A literal plus sign.
[1-9]
The first digit of the country code: never 0.
\d{1,14}
One to fourteen more digits, so 2 to 15 in all.
$
End of the string.

Matches

  • +14155552671
  • +48123456789
  • +442071838750

Doesn't match

  • 0048123456789
  • +0123456
  • +1 415 555 2671
  • +1234567890123456

In your language

JavaScript
/^\+[1-9]\d{1,14}$/

A literal; new RegExp(source, flags) builds the same from a string.

Python
re.compile(r"^\+[1-9]\d{1,14}$", re.ASCII)

A raw string, so backslashes reach re as written. re.ASCII keeps \d to 0-9, as in JavaScript (Python matches any Unicode digit otherwise). Use re.fullmatch to test a whole string.

Java
Pattern.compile("^\\+[1-9]\\d{1,14}$")

A normal string literal, so every backslash is doubled. matcher(s).matches() tests the whole string.

Go
regexp.MustCompile(`^\+[1-9]\d{1,14}$`)

A raw string in backticks. RE2 runs in linear time but has no lookaround and no backreferences.

PHP
preg_match('/^\+[1-9]\d{1,14}$/D', $input)

PCRE with / delimiters inside a single-quoted string. Without the D modifier, $ also matches before a final newline, so it is added to patterns that end in $.

C#
new Regex(@"^\+[1-9]\d{1,14}$", RegexOptions.ECMAScript)

A verbatim string: backslashes stay, a quote is doubled. RegexOptions.ECMAScript keeps \d to 0-9, as in JavaScript. $ also matches before a final newline; to reject one, end the pattern with \z instead.

Common mistakes

  • Strip formatting first

    People write +1 (415) 555-2671. Remove spaces, dashes, dots and brackets before matching, rather than making the pattern accept them.

  • Shape is not existence

    The pattern checks the length and the first digit only. Whether a number can exist depends on the country's numbering plan; Google's libphonenumber knows each one.

  • National numbers need a country

    A number typed without + (0612345678) can only become E.164 if you know which country it is from. Ask for the country, or default to the user's.