Changing the "From" number or Sender ID for outgoing SMS messages can be accomplished by changing the From parameter in your API requests.
For example:
An alphanumeric sender ID of up to 11 characters can be used for sending messages to all supported countries where pre-registration is not required.
Here’s an example cURL script - notice the From parameter updated in line 4.
-d "Body=Hello there" \
-d "To=+12685551234" \
-d "From=MyCompany" \