Hi AnnieL2,
Thanks for your response. Here is the case: My Apple ID is my email address with which I can sign in to my Apple ID....no problem there. There is no phone number associated with my id. Why have I done this way? I feel silly saying this but I don't know. I will have to ask the me in 2014! I don't remember at all. My trusted number listed on my id is my husband's phone number. I am guessing this is because in future if I ever I need to recover etc., his phone number would be accessible to me.
Recently, I decided to give my old iPhone 7 Plus to my 10 year old child. Therefore I erased all my data and created a new Apple ID for him. I wasn't allowed to create an id using an email possibly because he is underage. At the time, I hadn't taken a phone number for him therefore I used my phone number to create his id because I was under the understanding that at a future date, I could easily change his id (my phone no.) to his new phone number. I also added him to my family sharing.
Till a few days back, I was able to sign in using his id which is my phone number. I tried to change his id to his new number and the message I got was that it could not be done. Why was this?
Anyway, now I can't sign in using his id as apple says "this id is not supported or not valid".
If at all, I need to start all over again by erasing the iPhone 7 plus, I can even do that because I feel something has gone terribly wrong somewhere and I have gone into a loop. What do you say?
And how do I go about it?
Thanks in advance.
Lilysen