Number not registered

[myj697]

Whenever I try to send a message on my ipad using messages. I get the following message " number not reg.". I don't know how to fix it. The persons I am trying to reach have I phones.

 

[Wolfpuppies3]

When in doubt, go to the horse's mouth:

iOS: About Messages

 

[Mesqueunclub]

Whenever I try to send a message on my ipad using messages. I get the following message " number not reg.". I don't know how to fix it. The persons I am trying to reach have I phones.

Good advice from myj697. They may have iPhones/iPads/iPods but they have to register for messages. Simples (I think).
Easiest thing to do is contact them and ask. Hope this helps