# Phone number formatter: run it free, or from your agent

Turns a list of phone numbers into E.164, international and national formats and flags wrong lengths.

## Prompt

Use looot to clean these phone numbers: [paste numbers, one per line]. The default country is [country]. 1. Set up https://looot.ai/skill.md. 2. Put every number in E.164 format and flag the ones with a wrong length. 3. Search the catalog for a phone validation endpoint, check its price, and validate the flagged ones. 4. Return a table of input, E.164, country and verdict, and the total cost.

## What it needs

Phone numbers, one per line, and a default country

## What comes back

- E.164 format, such as +14155552671
- international format
- national format
- the country of each number
- the reason a number is flagged

## Endpoints and providers

- tomba: tomba-phone-validator

## What it costs

Nothing. The tool on the web page runs in the visitor's browser: no account, no API call and no limit per hour. The prompt above runs the same job from your own looot account with current data, billed per call.

## Prepare a CRM import

Put every number in E.164 so the CRM and the dialer read them the same way.

## Catch typos

See which numbers have too few or too many digits before you call or text.

## Ready for SMS tools

Most SMS and calling APIs ask for E.164. Copy the column and paste it.

## Check one number deeper

Run a flagged number through the phone carrier lookup for line type and carrier.

## What is E.164 format?

The international standard way to write a phone number: a plus sign, the country code and the number with no spaces or trunk 0, such as +14155552671 or +442079460000.

## How do I format a list of phone numbers?

Paste them in the box, one per line, and pick the country used for numbers without a + sign. Every line gets E.164, international and national formats. Download the result as CSV.

## Does it tell me if a number is real?

No. It checks the length and the prefix rules of the country. A number can have the right shape and still not be in service. Use the phone carrier lookup for a live check.

## Which countries does it know?

37 countries, including the US, Canada, the UK, most of Western Europe, India, Brazil, Mexico, Japan and Australia. A number from another country is flagged as an unknown country code.

## What happens to a number like +44 (0)20 7946 0000?

The 0 in brackets is the trunk prefix used inside the UK. The formatter drops it, so the E.164 form is +442079460000.

## Is this phone number formatter free?

Yes. It runs in your browser, needs no account and has no limit. Nothing you paste is sent anywhere.

## Why is the national format grouped the way it is?

Each country uses the grouping most common for its numbers. Some area codes group differently, so check the national form before you print it.

## Related tools

- /free-tools/phone-carrier-lookup
- /free-tools/csv-deduplicator
- /free-tools/email-signature-generator

## Last reviewed

2026-10-14.

## Agent skill for this page

https://looot.ai/free-tools/phone-number-formatter/skill.md sets an agent up for exactly the jobs on this page, with the live price of each, and offers the page's starter task once the user has picked a job and seen the price. The line to give an agent is under "Give this to your agent" below.

## For agents

### Give this to your agent

```text
set up looot for Phone number formatter - https://looot.ai/free-tools/phone-number-formatter/skill.md
```