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Reduce undeliverable messages, identify local-friendly number formats, and resolve caller names with Twilio Lookup. Find phone types, carriers, and more; Lookup allows you to programmatically get information about phone numbers so you can be as effective as possible.

In this example, we're using Lookup to access the Line Type Intelligence package to retrieve line type information about a phone number from the carrier:

curl -X GET '' \

Get Started with Lookup

Knowing your users is only a few lines of code away. Choose your programming language and dive into the quickstart, which will get you started using Lookup in:

  • PHP
  • Python
  • Node.js
  • C#
  • Ruby
  • Java
  • Go
  • cURL

Check out the Lookup Quickstart here.

Tutorials & Use Cases

1. Filter Out VoIP Numbers

Detect VoIP phone numbers, which can be often correlated with bots, before sending an SMS using Lookup's Line Type Intelligence package.

2. Filter Out Landline Numbers

Identify landline phone numbers to catch undeliverable SMS messages proactively and avoid unnecessary delivery charges using Lookup's Line Type Intelligence package.

3. Detect a SIM Swap

Detect a SIM swap that could be indicative of potential fraud before sending an one-time password (OTP) using the Lookup's SIM Swap package.

Build Your App

API Reference

Dive deeper into Lookup with our REST API reference and code samples.

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