Selling or Repairing Your Mac: How Do You Protect Your Files?

The situation

Your Mac needs a repair. The counter asks for the login password so they can test it.

The same Mac may be sold or handed down later. The two cases need different steps, so this page covers both.

What actually protects you

1. Ask why

   Hardware repairs often need no login. Ask if a temporary account is acceptable.

2. Back up first

   Use Time Machine or copy your files to a drive that stays with you. Apple says a backup matters in case the service means erasing or replacing the startup disk.

3. Follow Apple's service checklist

   Apple says to turn off Find My Mac on macOS 26 or earlier, and to turn on Ready for Repair or Trade-In on macOS 27 or later. Menu names depend on your version.

4. Create a temporary admin account

   Add it for the technician in System Settings > Users & Groups, and delete it afterwards. Do not give out your own login.

5. Keep private files encrypted and unmounted

   An encrypted disk image that is ejected shows as a file and nothing more. Apple's service page also lists turning on FileVault, or removing your data, as ways to protect it during service.

6. Change your password afterwards

   Do this if you shared it.

Selling or handing down the Mac

1. Back up with Time Machine or by copying your files to a drive you keep. Apple says the erase removes all the information from the Mac.
2. Sign out of your Apple Account, iMessage and any app that ties a licence to this Mac.
3. Erase the Mac. In System Settings > General > Transfer or Reset, choose Erase All Content and Settings. Menu names differ on older macOS versions. Apple says it needs macOS Monterey 12 or later on a Mac with Apple silicon or an Apple T2 chip. It erases all volumes and all user accounts, signs you out of Apple services, and turns off Find My and Activation Lock.
4. If the option is missing, Apple's manual route is to sign out of iCloud and iMessage, erase the disk from macOS Recovery with Disk Utility, and reinstall macOS. Then press Command-Q at the setup screen so the next owner starts fresh.
5. Do not rely on deleting files. Dragging files to the Trash does not erase a disk. Apple says items are not deleted until you empty the Trash. Erasing the Mac does the real job.
6. Check your backups. Old backups still hold everything. Keep them private or encrypt them.

What these steps do not cover

• A working login. A technician signed in to any account can read the unencrypted files that account can reach.
• An unlocked disk. Once a password you typed has unlocked the Mac, FileVault no longer limits what that session reads.
• Your backups. Apple says anyone who gets an unencrypted backup disk can read what is on it.
• Cloud copies. Erasing one Mac does not delete what you keep in iCloud. For iCloud Photos, Apple says the library stays in iCloud for your other devices.
• Older Macs. A Mac that cannot use Erase All Content and Settings needs the manual route. A Windows install made with Boot Camp can also block the erase until you remove it, Apple says.

How to test it

1. Before the repair, open your backup and open a few files from it. An erase cannot be undone.
2. Sign in to the temporary account and try to open your own account's Documents folder. Nothing private should open.
3. After an erase, Apple says the Mac displays "Hello" on a setup screen. If a login window with your name appears, the erase did not finish.

A five-item checklist

• You have a current backup.
• You asked what the technician needs.
• You used a temporary account.
• Private files are in a locked container.
• You changed passwords afterwards if you shared them.

Where a vault fits

A locked Hidden Folder vault contains only ciphertext. A technician with your login still cannot open it without the pattern. The lock-on-sleep and idle rules mean it is not left open. Vault files sit in one store under random names, not in Documents or Desktop. A vault does not replace an erase: before a sale you still erase the Mac. A planned encrypted iCloud backup would let a new Mac restore your vault with the 9-word recovery sentence, so keep it on paper.