We have 2 iPads, 2 iPhones and 1 Apple ID. How can I add the 2nd iPhone number? Would like to have my iPad FaceTime & messages associated with my iPhone; my husband's iPad FaceTime & messages associated with his iPad.
1 Apple ID is the problem.
You'd need to remove the ID as a contact source & just use the phone numbers.
Settings > Facetime
Same settings for iPad, just laid out slightly differently