> ## Documentation Index
> Fetch the complete documentation index at: https://developers.telnyx.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Telnyx Number Lookup API

> Use the Telnyx Number Lookup API to retrieve carrier, line type, and portability data for any phone number worldwide before routing or messaging.

The Telnyx Number Lookup API returns real-time data about any phone number worldwide, helping you make routing, messaging, and fraud decisions before connecting or sending.

## What Number Lookup returns

* **Carrier information** — Identify the current carrier and original network operator for any number.
* **Line type** — Determine whether a number is mobile, landline, VoIP, or toll-free.
* **Portability status** — Check whether a number has been ported from its original carrier.
* **Caller name (CNAM)** — Retrieve the registered caller name associated with a US number.
* **National and international format** — Get consistently formatted number representations.

## Common use cases

* **Message routing** — Route SMS vs. MMS based on line type and carrier capabilities.
* **Fraud prevention** — Flag high-risk number types (VoIP, prepaid) during account signup or transaction verification.
* **Number hygiene** — Clean contact lists by identifying disconnected, invalid, or non-mobile numbers before launching campaigns.
* **Pre-call validation** — Verify number reachability before placing outbound calls to reduce wasted call attempts.

## Get started

<CardGroup cols={2}>
  <Card title="Quickstart" icon="bolt" href="/docs/identity/number-lookup/quickstart">
    Look up your first phone number in a few lines of code.
  </Card>

  <Card title="API Reference" icon="code" href="/api-reference/number-lookup/look-up-phone-number">
    Full endpoint documentation with request and response schemas.
  </Card>
</CardGroup>