Lookup Quickstart

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, reduce the likelihood of undelivered messages and protect yourself from fraud.

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. lookups.twilio.com/v1/PhoneNumbers/{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 "https://lookups.twilio.com/v1/PhoneNumbers/5108675309?CountryCode=US&Type=carrier" \
    -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 twilio-php helper library makes this extremely easy. Open a file called lookups.php and add the following lines:

// Get the PHP helper library from twilio.com/docs/php/install
require_once('/path/to/twilio-php/Services/Twilio.php'); // Loads the library

// Your Account Sid and Auth Token from twilio.com/user/account
$sid = "{{account_sid}}";
$token = "{{ auth_token }}";
$client = new Lookups_Services_Twilio($sid, $token);

$number = $client->phone_numbers->get("(510) 867-5309", array("CountryCode" => "US"));
echo $number->phone_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:


$number = $client->phone_numbers->get(
  array("CountryCode" => "US", "Type" => "carrier")

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