Account

My son has recently tried to log on to the US version of itunes to download an album. Obviously this wouldn't have worked and didn't, however itunes will not allow him to log back into the UK itunes. I've tried removing him from family settings on music and invited again but he says that it is something to do with icloud idm? He hasn't tried to sync again with a computer although I'm not sure if that would help? Does anybody have any suggestions?