United States phone number validator
How the phone number format works
- Format
- United States phone number in national or international (+1) format
- Example
- +12015550123
Things to watch for
- Accepts national or international (E.164, e.g. +1...) format
- Validated with Google's libphonenumber; confirms the number is possible/valid for this country, not that it is currently assigned or reachable
^[+]?[0-9 ()\-]{6,}$A US phone number is a standard 10-digit North American Numbering Plan (NANP) number — a 3-digit area code plus a 7-digit local number, e.g. 415-234-5678 for San Francisco — the same shape shared with Canada, Bermuda, and a long list of Caribbean nations and US territories under the same NANP umbrella. What makes a number specifically American is its area code: 212 and 646 (New York), 415 (San Francisco), 312 (Chicago), and hundreds more are assigned to the US within the shared +1 range, distinct from the Canadian area codes covered on this site’s Canada page.
How this validator works
Type the number in local form (415-234-5678) or full international form (+14152345678); this tool checks the digit count and confirms the area code falls within a range assigned to the US using Google’s libphonenumber, entirely client-side. Because NANP membership is shared across so many countries and territories, a bare “10 digits starting with a plausible area code” check can’t say American on its own — libphonenumber’s per-country metadata, distinguishing US-assigned codes from Canadian or Caribbean ones, is what makes that call possible.
What a pass doesn’t tell you
A pass confirms the number has a real US-assigned area code and a plausible 7-digit local number — it does not confirm the line is connected, ported, or currently held by the person who gave it to you.
Scope: format and area-code-origin validation only, useful for catching a mistyped digit or a wrong-country assumption before a number reaches a CRM or dialer — not a substitute for a carrier lookup.
Content last reviewed 2026-07-07.
phone number FAQ
If a number passes this US check, does that prove it's American rather than Canadian?
Not by itself. The US shares the North American Numbering Plan (NANP) with Canada and roughly two dozen other countries and territories — Bermuda, Puerto Rico, Jamaica, and more all dial as +1 with the same 10-digit shape. This validator confirms the area code falls within the range assigned to the US specifically, which narrows it down, but +1 alone is never proof of the US on its own.
Why is a US phone number 10 digits, and where does the leading 1 fit in?
The 10 digits are a 3-digit area code plus a 7-digit local number, e.g. 415-234-5678 for a San Francisco line. The 1 sometimes written before it is NANP's long-distance access code, not part of the number itself — both 415-234-5678 and +14152345678 are correct, but +1 1 415... with an extra 1 after the country code is not.
Does a valid US area code mean the number is currently active?
No. It only confirms the area code and local-number shape match a real US NANP pattern — it can't confirm the line is connected, ported, or still held by whoever gave it to you, since US carriers reassign disconnected numbers after a dormancy period.