I tried to do it last night, and it said one of my accounts was ineligible. Didn't say which one, or why it was ineligible. I got on a live chat with Apple Support... for 2 hours. Surprisingly, the dude had already been very very trained on the ins and outs of the migration process. He knew everything.<p>You can’t migrate purchases if both of your accounts have Apple Music libraries. This is minor, as you can get around it by simply deleting everything out of the primary (aka non-purchasing) account. He did know that it will also migrate iTunes Match, though, which I had been worried about since it's not mentioned in any of the support documents, and it doesn't even show up in my subscription list. He said they include iTunes Match as part of Apple Music itself, so it's not listed separately.<p>The MUCH bigger deal (especially if you use Family Sharing) is that you cannot have shared your iCloud storage more than 1 other account. Well, I have a wife, 2 kids, and my purchases account. The only way around this is for me to disband my “Family”, then do the migration, then re-create my family… BUT it’s not that easy, because kids MUST be in a family. SO, first my wife has to create a Family. Then I disband my Family and transfer the kids to hers, where she’s the organizer, not me. Then I do the migration. Then I rejoin the family, but she hates tech, so I need to be the organizer, so then she has to leave her own Family, which will make me the organizer by default. Then she can join back. Then we should be ok… except that during that whole time they will have zero iCloud storage (it’s all on my account), and no access to our subscriptions (all on my account), and no access to family shared apps… AND if anything goes wrong, we’re in a huge effing mess.<p>Oh, and I forgot to ask if or how it would affect our Photos library, where my wife and I each have a private library, but also share a library with 150k photos and videos in it.