Pairing the phone messages to the ipad

If you have an iPhone - and both iPad and iPhone are signed-in to iCloud with the same AppleID, to send SMS/MMS messages from your iPad you must explicitly enable Text Message Forwarding for your iPad on your iPhone. Verify these settings:

On your iPhone:

Settings > Messages > Text Message Forwarding - set to ON - and explicitly enable your iPad from the list of devices.

Also ensure that Messages in iCloud is enabled on both your iPhone and iPad:

Settings > [Your Name / AppleID] > Messages - set to ON

Hello Xxercise,

​Thank you for using the Apple Support Communities. It looks like you're running into an issue using Messages on your iPad, and we'll be happy to assist.

To clarify, are you referring to Text Message Forwarding, or to setting up Messages in iCloud?

For forwarding, check out this link for the steps. This should help you get set up: How to forward SMS/MMS text messages from your iPhone to your iPad, iPod touch or Mac

On the other hand, if you mean Messages in iCloud, this link will help you to Set up iCloud for Messages on all your devices.

If the issue persists, please reply back here with the details of what's happening when you try setting it up, and we'll go from there. Take care.