Register by 10/16 for $250 off the on-site price.

Error 21601

Error - 21601

Phone number is not a valid SMS-capable/MMS-capable inbound phone number

The phone number you provided as the FROM field to initiate an outbound message is not an incoming phone number assigned to your account. Only phone numbers that you buy from Twilio can be used for outgoing messages. In particular, 3rd party phone numbers such as validated CallerIDs cannot be used to send messages.

Need some help?

We all do sometimes; code is hard. Get help now from our support team, or lean on the wisdom of the crowd browsing the Twilio tag on Stack Overflow.