Shirley Last Name Withheld wants to help her boss, who constantly loses his phone, without having her data get intermingled with his. She notes:
Although I sign into iTunes using his Apple ID—say boss@yahoo.com—and sync his phone with iTunes, all my data (photos, contacts, etc.) goes into his phone as well. How can I separate his stuff from mine?
If he’s switched entirely to iCloud syncing, iCloud backups, and iCloud Photo Library, you could avoid using iTunes altogether, but it sounds like that might not be in the cards. If you can make that happen, you’ll probably need to make sure he has 50GB or 200GB of paid iCloud storage as well.
Failing that, on your Mac, set up a separate user account, and log into his Apple ID on that account.
- Open the Users & Groups system preferences pane.
- Click the lock and enter your administrative password.
- Click the + sign in the lower left to create a new account on the computer. (This isn’t a new Apple ID or iCloud account; it’s just on your machine.)
- While following the steps for that new account, you can opt to have it use the same login information he uses with iCloud.

Enable Fast User Switching in order to set up separate accounts with their own iTunes and iCloud syncing.
- Under Login Options in the same window, check the box for “Show fast user switching as”. This lets you stay logged into multiple OS X accounts at once and switch begin them.
- From the Fast User Switching menu in the menu bar, select your boss’s account. OS X will switch to that account and ask you to log in while leaving your session running.
- In his account, launch iTunes and log into his account.
- Assuming he’s syncing contacts and calendars via iCloud, open the iCloud system preferences pane, and enter his Apple ID there as well and set up the categories he syncs.
If he’s not using iCloud for backup and iCloud Photo Library, you’ll need to log into that account and connect his phone via USB for routine syncing and backups.
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