E.164 phone number formatter

How to use the formatter

• Type or paste the number. Spaces, dashes, dots and parentheses are ignored.
• If the number starts with + or 00, the country is detected from the code and the selector is ignored.
• If it has no country code, select the country; a leading trunk prefix (0 in most of Europe and Asia, 1 in North America, 8 in Russia) is removed automatically.
• Read the status line: green means the length matches the country's numbering plan, amber means the number only passed the generic E.164 check, red means the length is wrong.
• Copy the format you need. E.164 is what sign-up forms and APIs want; RFC 3966 is the tel: link you put in a web page.

The four formats explained

Length rules for 57 countries

The table lists the number of digits a national number has after the country code (trunk prefix removed) in the countries that account for most verification traffic. Ranges reflect plans with variable-length numbers; Germany and Austria, for example, allow anything from six to thirteen digits. Countries not in the table are checked against the E.164 envelope only: at least six digits and at most 15 in total including the country code.

Why format matters for SMS verification

Apps that send verification codes normalize what you type into E.164 before handing it to their SMS provider. When the normalization guesses wrong, the code goes to a number that does not exist and you see nothing. The classic mistakes: keeping the trunk 0 after the country code (+44 07911… instead of +44 7911…), typing a national number into a form that already shows the country code, or picking the wrong country in the dropdown. If a form rejects a temporary number from our catalog, paste the number here first and compare the E.164 output with what the form shows.

What this tool does not do

• It does not check whether a number is assigned, active or reachable, and it does not tell mobile numbers from landlines.
• Length rules exist for 57 countries; everywhere else only the E.164 limit is checked, so a wrong length can pass.
• Shared country codes are resolved by a short list of prefixes (Canada's area codes, Kazakhstan's +7 6/7, Mayotte inside +262, NANP overlays). Guernsey, Jersey and the Isle of Man are shown as United Kingdom; Vatican City as Italy.
• Germany and Austria have very flexible plans, so a national number typed with its country code but without + cannot always be told apart from a long national number. Add the + when you include the country code.
• Grouping in the international and national formats follows common conventions, not every carrier's house style.