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Lookup v1 Quickstart

Version 2 of the Lookup API is now available! Lookup v2 has an improved developer experience and exciting features, such as Twilio Regions support and these new data packages:

  • Line Type Intelligence: Get the line type of a phone number including mobile, landline, fixed VoIP, non-fixed VoIP, toll-free, and more.
  • SIM Swap: Get information on the last SIM change for a mobile phone number.
  • Call Forwarding: Get the unconditional call forwarding status of a mobile phone number.
  • Identity Match: Get confirmation of ownership for a mobile phone number by comparing user-provided information against authoritative phone-based data sources.

You are currently viewing Version 1 content. Lookup v1 will be maintained for the time being, but any new features and development will be on v2. We strongly encourage you to do any new development with Lookup v2. Check out the migration guide or the API v2 Reference for more information.

How to look up a Phone Number

What is Lookup?

Lookup allows you to systematically ascertain information about phone numbers. With Lookup, you can identify local-friendly number formats and reduce the likelihood of undelivered messages.

Looking up a Number

First, decide what you’d like to know about your numbers. Format lookups are free and allow you to identify and adjust international phone numbers into E.164 format for optimal message deliverability. Carrier lookups cost $0.005 per lookup and allow you to identify both the phone type (mobile, landline or VoIP) and the carrier behind the phone number.

Let's look at the details:

  • First log into your Twilio Account. On the Dashboard there is a section labeled "API Credentials". There you will find your Account SID and Auth Token. You'll need these to authenticate your request.
  • To perform a Lookup, we'll be making a HTTP GET request to the lookup subdomain.{PhoneNumber}
  • We will need to include the phone number we want to look up.
  • We may then specify any additional information as GET parameters.

Let's try this out by using curl to make the following request in our terminal:

curl -XGET "" \
    -u '{AccountSid}:{AuthToken}'

Format Lookup

Now we want to integrate Lookup with our application. Let's try it out with our helper library.

You may want to use Format Lookup in order to reformat international numbers given to you by your customers in local format. In this case, you need to specify the number and the country you believe the phone number is from. Note that this lookup is free.

Our helper libraries makes this extremely easy. Open a new file and add the following lines:

Loading Code Sample...

        Lookup with National Formatted Number

        You'll want to include the country code of the phone number that you would like formatted. If not included, the country code will default to the US.

        Carrier & Type Lookup

        You may also want to do a lookup to determine the phone number type and carrier for your phone number. Note that this costs $0.005 per lookup.

        To do this lookup, you'll want to include the carrier parameter. Similar to the code above, we can make this request with the following snippet:

        Loading Code Sample...

              Lookup with National Formatted Number

              Now you're ready to look up your customers' phone numbers and reach them in the most appropriate ways!

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              Need some help?

              We all do sometimes; code is hard. Get help now from our support team, or lean on the wisdom of the crowd by visiting Twilio's Stack Overflow Collective or browsing the Twilio tag on Stack Overflow.

              Loading Code Sample...

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