use mobile number as default for messages

BuddyJ167 wrote:

I see that > symbol next to all the other names that show up but not by his name.

Here are some reasons that come to mind:

• Perhaps he has not allowed both his Apple ID and iPhone telephone number at Settings > Messages > Send & Receive > [You can receive iMessages to and reply from]
• Perhaps you don’t have both his iPhone telephone number and Apple ID on his entry in your Contacts

I apologize. What you should see next to your son’s name (assuming he’s in your Contacts) is a greater than sign, not an “I”.

Tap the circled “I” to the right of his name. Then choose the iPhone telephone number if you wish.

There will be absolutely no difference in the message transmission.