---
ref: tool:twilio/look-up-phone-number
name: Look up a phone number
company: company:twilio
workflows: []
access: [cli]
tags: [capability:enrich-contacts, category:messaging, has:cli]
docs: https://www.twilio.com/docs/lookup/v2-api#making-a-request
updated: 2026-09-27
---

# Look up a phone number

Validates a phone number and returns it in E.164 and national formats, plus line type, caller name or other data you request.

Note: Pass the number in E.164 format. The basic lookup is free; data packages added with `--fields`, such as `line_type_intelligence` or `caller_name` (US only), are paid, and some need Twilio's approval first.

## Set up

Use the first option your agent supports.

### CLI (official)

Install the command, then confirm it runs.

```sh
brew tap twilio/brew && brew install twilio
twilio --version
```

Run `twilio api:lookups:v2:phone-numbers:fetch`.

Set `$TWILIO_API_KEY` in your environment first (get a key: https://www.twilio.com/docs/iam/api-keys/keys-in-console).

Note: Also set `TWILIO_ACCOUNT_SID` and `TWILIO_API_SECRET`, with `TWILIO_API_KEY` holding the API key SID, or sign in once with `twilio login`.

Before anything else, confirm access with the cheapest read-only call, like a list or a search. Never send or change anything to test access.

## Rules

- Ask the user before anything that sends messages, costs money, or changes data, and say how many records it touches. One approval covers a batch the user has seen.
- Never print API keys.