Twilio allows you to set the caller ID on outbound calls to a number you have verified that you own. We use this to set caller ID to office phone line for example. This is done by setting the "From" parameter when creating a call. https://www.twilio.com/docs/voice/api/call-resource#create-a-call-resource To avoid spoofing, twilio first verifies that you own it before you can use it: https://www.twilio.com/docs/voice/api/outgoing-caller-ids#http-post For my needs, I will be importing phone numbers that we already own from my own twilio account, so we don't need you to implement the caller ID registration, I only need a way to set the "From" on calls.