Why did I receive a 4720 messaging error?

If you received an error code 4720 Carrier Rejected as an Invalid Destination Address, this could mean the number is not in the numbering plan (the area code doesn't exist or the number is just invalid) or it's not enabled for messaging (like a landline). Additionally, for toll-free messages to T-Mobile, this could also mean the user has opted to block all toll-free and short-code traffic. For more messaging error codes, see our dev docs.