I had thought one couldn't upon reading the text on Apple's website, "Once a device or computer is associated with your Apple ID, you cannot associate that device or computer with another Apple ID for 90 days." Recently, though, someone has told me that is is indeed possible to switch as often as you want.
Which is the case? I'd prefer someone with firsthand experience.
Yes - you can switch accounts on one device many many many times. Once you have associated that account with that device, it uses one of your 10 slots for the next 90 days. After then, that device doesn't count as a "new device" for your limited slots.
The text "You may switch an Associated Device to a different Account only once every 90 days" appears twice in the current iTunes, Mac App, App Store and iBookstore T&C under two subsections:
So - if you take one of the many accounts that can exist on one device - only one account gets the "automatic" pushing of content purchases prior or elsewhere until the 90 day timeout expires.
Other than that one restriction, think more about your account rather than the specific device. Accounts are intended for one person, so when you create it, you can't go and use it on 11 devices after the tenth new device your account hits, you need to wait 90 days from the first device to account pairing.
It doesn't matter what other accounts are on a specific device - its about your ID being used in the app store on multiple devices.
For questions like this here are some nice references:
I was puzzled by that comment too, since from first-hand experience I can tell you that I am able to frequently switch between 3 different Apple IDs on my iPad and on my Mac. I switch maybe weekly for one reason or another.
There is a distinction between "switching" the active Apple ID and making new associations. My iPad is associated with all 3 of the Apple IDs I use, although I am the primary user of only one of them. On the rare occasion that I've had to associate a single Apple ID with two totally new devices, I haven't run into a 90-day limit.
(EDIT: To clarify when I think I've violated the 90 day policy without difficulty, I bought a new iPad for my mother. We went through the process of creating an Apple ID for her, and buying a few apps. Then I switched over to my own Apple ID to download a few apps that I had previously purchased. Then I switched her back to her own ID. My interpretation is that I associated her device with two different Apple IDs without having to wait 90 days between associations.)
Its more than easy to switch Apple ID's but to be able to download your purchases music is another story. I have a Mac Mini and my dad recently updated it so that Apple Music would be available. He then logged in to his user and created his Apple Music account. Now when I go on my user, I have tried to download some things that I have purchased from the iTunes Store, or even trying to make a track available offline from Apple Music and I am faced with the "This computer is already associated with an Apple ID" message.
