iPhone 13 and suddenly stopped being able to send text messages
my IPhone 13 suddenly won’t send or receive text messages to one number
iPhone SE, iOS 14
Question marked as
Read the article linked above. Determine if the messages are SMS or iMessages.
If they’re SMS, it’s a cellular carrier issue unless the other person is a former Apple person who failed to de-register iMessage.
Deregister iMessage on your iPhone or online - Apple Support