I'm trying to add my sons Gamertag to my XBOX One. It has identified him as being part of our family and when I select "Add to this XBOX" it takes me through the parent authentication process. It gets to the point where it tells me it needs a credit card to authenticate, but only gives me the option to "Add a Card" even though I have one registered on my account.
When I go through the process of adding a new card, once this is completed, it goes back to the screen with the "Add a card" option and I cannot progress any further.
Does anyone have any solutions?