The family accounts are crazy anyway. I once worked for an agency that had just bought its first Windows Phone for testing. Setting it up I dutifully signed in with the company’s MS account, but found that I couldn’t install any apps and there were loads of restrictions. It took me multiple hours of debugging to realise that because someone at the past had entered the company’s formation date in the birthdate of the MS account Windows Phone thought I was a child and blocked me from doing a load of the things I needed to do.