When using our Simply Text account to send text messages to students, we’re required to input a cell phone carrier in order to make sure the text messages get delivered. From time to time a carrier will be wrong and they will be removed from messaging, or we never got the carrier info in the first place. It isn’t always just as easy as asking a student for their correct information, especially since we promote joining the list at our entry-level programs and services.
I just found this website that allows you to lookup the carrier of any number (area code and prefix). We’ve added back in quite a few of those numbers that were stalled now and are back in business! If you’re already using the system (sign up for a full-featured 30-day free trial if you’re not) this should be a big help.