Adding a Verified Phone Number or Caller ID with Twilio

An existing non-Twilio phone number, like the number to a wireless phone or a landline in your home or office, can be verified on your Twilio project to be used for testing with a free trial account, or as a caller ID on outbound calls. Continue reading for instructions and important information.

Please note: Verifying a caller ID with Twilio only allows calls to be placed outbound (from Twilio) using this phone number. Incoming calls to the verified number will continue to route through the existing service provider. If you would like to receive incoming calls through Twilio, we may be able to port your phone number in. For more information, please see our article Porting a Phone Number to Twilio.

Add a Verified Caller ID via the Console Site

  1. Login to your account at
  2. Click Phone Numbers Icon_Numbers.png.
  3. Click Verified Caller IDs.
  4. Click the red + sign icon Icon_New.png, or Verify a number.
  5. Enter the desired phone number to verify, and then click Call Me.
    NOTE: Click Text you instead to receive a text message for verification.

Add a Verified Caller ID via the REST API

A verified caller ID can be added to your project by submitting POST request to the Outgoing Caller IDs resource. For full details, please see our API documentation for Adding an Outgoing Caller ID.

Verifying Caller IDs Behind an IVR or Extension

You can verify numbers behind IVRs using both the above methods by including w characters in the Extension parameter. Each w character tells Twilio to wait 0.5 seconds instead of playing a digit. This lets you adjust the timing of when the digits begin playing to suit the phone system you are dialing.

For example, the extension wwww2wwwwww5wwwwww9 waits two seconds before sending the digit 2, followed by a three second wait before sending the 5, and finally another three second wait before sending a 9. You will need to tune the extension to the IVR system to be able to programmatically verify numbers behind IVR menus.


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