Hey vk0424,
Thank you for visiting Apple Support Communities.
It seems like your Apple ID (iMessage account) doesn't include your phone number on your iPad.
You mentioned that you've signed out and back in to Messages on your iPad, but there was no change.
If you're on a first generation iPad, this feature isn't available, as mentioned in iOS and OS X: Link your phone number and Apple ID for use with FaceTime and iMessage.
This feature isn't available on iPod touch (3rd generation) and iPad (1st generation).
For a newer iPad, try signing out of both Messages and FaceTime. If your phone number still isn't linked to the device, sign out of Messages and FaceTime on all of your iOS devices. Then sign back in on your iPhone and iPad.
Here are the detailed steps you can follow:
If your phone number isn't listed on an iPod touch or iPad, follow these steps:
- Update to the latest version of iOS.
- Verify that you're using the same Apple ID that you're using on your iPhone.
- On your iPad or iPod touch, sign out of your Apple ID in the following locations:
- Settings > Messages > Send & Receive. Tap your Apple ID, then tap Sign Out.
- Settings > FaceTime. Tap your Apple ID, then tap Sign Out.
- Sign in to your Apple ID with FaceTime and iMessage.
If your phone number still isn't listed, follow these steps:
- Sign out of your Apple ID on all iOS devices, including your iPhone, in the following locations:
- Settings > Messages > Send & Receive. Tap your Apple ID, then tap Sign Out.
- Settings > FaceTime. Tap your Apple ID, then tap Sign Out.
- Sign in to your Apple ID on your iPhone.
- When activation is complete, your Apple ID and all verified email addresses should be visible in Settings > Messages > Receive At and Settings > FaceTime.
- Sign in to your Apple ID on your other iOS devices.
All the best.