Setting up a Mac to share with a partner
· 5 min read
Sharing a Mac usually starts as one login that both people use, because it is simpler. It stays simpler for about a month, until browser tabs, half-written messages and downloaded files start belonging to the wrong person.
Separate accounts fix nearly all of it and cost twenty minutes.
Separate accounts, one shared folder
System Settings, Users & Groups, Add Account. Make the second person an administrator if they are equally responsible for the machine, standard if they would rather not be.
Each account gets its own home folder, browser, mail, messages, desktop and settings. Nothing crosses over, which is the point.
For files you both need, /Users/Shared already exists and both accounts can read and write it. Add it to both sidebars. That single folder covers most of what people actually share: household documents, photos being sorted, a scanner output folder.
Fast User Switching
System Settings, Control Centre, then Fast User Switching, set to show in the menu bar.
This lets one person switch to their account without the other logging out or quitting anything. Applications stay open in the background and come back exactly as they were.
Worth knowing: a switched-away account is still running and still using memory. On a machine with limited memory, two heavy accounts at once can feel slow. Logging out properly rather than switching solves it.
What to share and what to keep separate
Keep separate: browser, mail, messages, notes, downloads. These are where the friction is, and they are personal by nature.
Share deliberately: files in /Users/Shared, printers, the Wi-Fi, and any household calendar.
Decide about photos. This is the one that needs an actual conversation. Options are a shared library on the Mac, iCloud Shared Photo Library, or each keeping their own and sharing albums. There is no obviously right answer; the wrong answer is not deciding and ending up with two partial libraries.
Decide about purchases. Family Sharing lets each person keep their own Apple Account while sharing App Store purchases, subscriptions and storage. That is nearly always better than sharing one account. Family Sharing covers what it does and does not cover.
Do not share one Apple Account
The arrangement that causes the most trouble later.
Sharing an account means both people receive each other’s messages and FaceTime calls, see each other’s photos, and share a contact list. It also means neither of you can leave with your own data intact, which matters more than it seems when the machine or the relationship changes.
Family Sharing exists precisely to give you the shared benefits without the shared identity.
The password question
Each account has its own login password, which is correct. What people ask about is whether to know each other’s.
That is a domestic decision rather than a technical one. What is worth saying: FileVault means a forgotten password on an account nobody else can unlock is genuinely a lost account. If only one of you administers the machine, make sure the recovery key is stored somewhere both can reach, or that there are two administrator accounts.
A shared Mac still needs one backup
Time Machine backs up the whole machine, all accounts, from either login. One drive covers both people.
Worth being explicit with each other that it exists and where the drive is, because the person who set it up is not always the person who needs to restore from it. A backup plan that survives one thing going wrong covers what is reasonable.
Guest access for visitors
Separate from all of the above. A guest account gives a visitor a working Mac for an hour with none of either person’s files, wiped on logout. Guest mode covers it.
Questions
Does a second account use much disk space? Only what that person stores. The system and applications are shared, so a second account starts nearly empty.
Can we see each other’s files? Not by default. Home folders are private between accounts. An administrator can reach another account’s files by authenticating, which is worth knowing.
Should both be administrators? If both are equally responsible for the machine, yes, and it means either can authorise changes. Two administrators also means a forgotten password on one account is recoverable via the other.
What happens if we separate? Each account’s files can be copied out to a drive and migrated to another Mac with Migration Assistant. Separate accounts and separate Apple Accounts make this straightforward, which is the strongest practical argument for the arrangement.