Phone numbers
E.164
E.164 is the international format for phone numbers: a plus sign, the country code, then the national number, with no spaces or punctuation and at most 15 digits.
How it works
Because it is unambiguous, E.164 is the form to store in a database and to send to an API. A US number written as (415) 555-0123 becomes +14155550123.
Display formats such as national and international styles are generated from the E.164 value when a person needs to read it.
Validating against E.164 checks structure: the plus sign, a real country code and a length of 15 digits or fewer. Passing means the number is well formed, not that anyone answers it, so pair it with a line-type or carrier lookup before you send a message or place a call. Strip spaces, dashes and brackets before storing, and keep the leading plus so a country code cannot be mistaken for a local prefix.
Related LookValid products
| Product | Credits | Docs |
|---|---|---|
| Phone Numbering-Plan Validation | 1 credit per valid number | API docs |
New to the API? Start with the quickstart or the API reference. Agents can call the same lookups through the MCP server.