Oh wow, you're right! I've always thought you could use a verified phone number as the "From" number, but it turns out that's true only for phone calls, not SMS

Oh wow, you're right! I've always thought you could use a verified phone number as the "From" number, but it turns out that's true only for phone calls, not SMS. From http://www.twilio.com/docs/api/rest/sending-sms http://www.twilio.com/docs/api/rest/sending-sms: Parameter Description From A Twilio phone number enabled for SMS. Only phone numbers or short codes purchased from Twilio work here; you cannot (for example) spoof SMS messages from your own cell phone number. If you haven't purchased a Twilio number yet you can use the Sandbox Number to send SMS to verified numbers. I've built many PoCs with Twilio but it seems that I've never tried to send an SMS on behalf of somebody. Good to know, very good to know.