---
title: "Free US phone number check"
url: "https://numberburn.com/tools/number-lookup.md"
canonical_url: "https://numberburn.com/tools/number-lookup"
last_updated: "2026-10-19"
type: "tool"
summary: "Check a US phone number in your browser: well-formed or not, E.164 and national format, area code and state. Nothing is sent or stored."
related: ["https://numberburn.com/tools.md", "https://numberburn.com/tools/spam-number-lookup.md"]
---

# Free US phone number check

Check a US phone number in your browser: well-formed or not, E.164 and national format, area code and state. Nothing is sent or stored.

Paste a US phone number and see whether it is well formed, how it looks in E.164 and national format, and which state or district its area code belongs to. It runs in your browser and nothing leaves the page.

## What it does

Enter a US phone number in any common format. The tool says whether it is a well-formed US number, shows the E.164 and national formats, and names the state or district of the area code. It is interactive on the page; this text describes it.

## Input rules

- Ten digits, with an optional leading +1 or 1. Spaces, dots, dashes and brackets are fine.
- The area code (first three digits) starts with 2 to 9.
- The exchange (next three digits) starts with 2 to 9.
- Only United States numbers count. Canadian and other numbering-plan codes are recognised and flagged as outside NumberBurn.

## What this tool covers

The check reads the numbering plan, so these details are outside its result. The spam number lookup covers line type, carrier and risk.

- Line type: mobile, landline or VoIP
- Carrier name
- Spam or scam risk

## How to read the result

| Field | What it tells you |
| --- | --- |
| Verdict | Whether the digits form a well-formed US number under the numbering plan rules. It does not say the number is in service. |
| E.164 | The international format, `+1` then ten digits. It is what most systems store. |
| National | The format Americans write: `(312) 555-0142`. |
| Area code | The first three digits and the state or district the table assigns them to. |
| Notes | Plain-language remarks, such as a Canadian code or a number range that is set aside. |

For line type, carrier and a complaint-based risk level, use the [spam number lookup](https://numberburn.com/tools/spam-number-lookup.md).

## What a good result does and does not mean

- A well-formed number has the right shape. Anyone can type a number that fits the shape and has never been assigned.
- The area code names where the code was assigned, not where the person is now. People keep their numbers when they move.
- Nothing here says whether a number is a mobile, a landline or an internet line, who carries it, or whether it sends spam.

## Where the area codes come from

Area codes come from the public report of the North American Numbering Plan Administrator, file dated 10/17/2026 (fetched 2026-10-17). Only geographic codes in service are kept. New codes are assigned a few times a year, so a very new code can show as not in the table until the list is refreshed.

## Privacy

The check is plain JavaScript on this page. The number you type is not sent to a server, not saved and not logged. There is no account and no cookie for it. Close the tab and it is gone.

> **Free means free:** The tool needs no sign-up and makes no network call, so there is nothing to meter and nothing to log.

## Area-code data source

North American Numbering Plan Administrator NPA report, https://reports.nanpa.com/public/npa_report.csv, file dated 10/17/2026, fetched 2026-10-17.

## Questions

### Does this tell me if a number is a mobile or VoIP line?

No. This tool reads the numbering plan, so line type, carrier and spam risk are outside what it reports.

### Is the number I type sent anywhere?

No. The check runs in your browser with no network call. Nothing is stored or sent, and there is no account.

### Why does a Canadian number show a warning?

Canada shares the +1 country code with the United States, so the format is valid. NumberBurn numbers are US only, so the result says the code is outside the service. See [pricing](https://numberburn.com/pricing.md) for what a NumberBurn number is.

## Next step
See [pricing](https://numberburn.com/pricing.md) for a number you can burn.

## Related

- [Free tools](https://numberburn.com/tools.md)
- [Free spam number lookup](https://numberburn.com/tools/spam-number-lookup.md)