There are a couple of places on your Mac where your name – or some other name – might appear: the account name and Home folder. The name that appears is based on the Full Name you gave when you (or the administrator) first set up the account.
But what if you want to change your username as it appears in these locations? It’s possible that you have since married and now have a new name (or you just divorced). Maybe IT misspelt your name when they set up your Mac. Perhaps your initial and surname spell something offensive, or it might be time to change what was once an amusing username for something more formal. Maybe your current short name isn’t really short and is a pain to type every time you’re prompted for your username. Perhaps you’ve got two or more Macs and you want to use the same short username on all of them. Or maybe you inherited a Mac and would prefer to just change the name of the existing account rather than create a new one.
Luckily, since Mac OS X Leopard launched in 2007, Apple has made it reasonably simple to change the short username and Home folder name from within System Preferences. Prior to Leopard, changing your short username was a complicated, risky procedure.
There are still a few limitations though:
The Short Name and Home folder name must match – so if you were hoping to give your Home directory a comedy name, but keen the short name as something more formal, you are out of luck.
Despite what we said about it being a less risky procedure, it is the kind of change that could result in data loss if you do something wrong. So make sure you back up first!
You can’t change the name of an account while logged into the account you’re changing. So you will also need to log in to a different (administrator) account to do this – you may need to create that first.
If you need to create a new administrator account follow these steps:
Alternatively you can make an existing account an administrator.
Open the Users & Groups preference pane.
Click the lock icon at the lower-left corner and authenticate yourself.
Select the account in the list at left.
Check the box “Allow the user to administer this computer.”
macOS notes that you have to restart your Mac for that to take effect; do so.
How to change Mac username
Now that you have set up this alternative administrator account it’s simple to change the user name for your account. But you will see a pretty stark warning that changing the settings might damage the account and prevent you from logging in, so do be cautious!
The first thing to do is log out of your account and into this new administrator account:
Click on the Apple logo and choose Log out [your name]
Then enter the new admin account name and password.
Now you are all set to change the username of your usual account. Follow these steps to change the username:
Open System Preferences.
Click on Users & Groups.
Click unlock and enter your password (for the admin account you are using).
Now Control-click or right-click the user that you want to rename.
Choose Advanced Options.
Change the name in the full name field.
Restart the computer for the changes to take effect.
This will only change the username – not the Home directory name, or your Short Name. And, as the warning states, it may damage the account and prevent you from logging in!
We did it without any problems, although there were a few hair-raising seconds when the login process took slightly longer than usual.
How to change Home folder name and Account name
Changing your Home folder name (and your account name, which is linked – and as you can see in the image above, grayed out) is more complicated.
As before you have to be logged out of the account to be able to change it. So if you aren’t already in the separate admin account log into that.
Here’s how to change your Home folder name and Account name:
Go to the Users folder on the startup drive (to find it open the Finder and click on Go > Computer)
This should open the Macintosh HD [or Untitled/whatever name your computer has] folder.
Inside the Macintosh HD folder is the Users folder – click to open that.
Inside the Users folder you will find the Home directory for the account you’re renaming. (Write this down as you will need it later).
Click on the folder and rename it. (Note the old and new name because you will need it once more).
Enter the password for the admin account you are using when prompted.
How to change your Username
Having changed your Home folder name you now need to change your Username – if you don’t there will be problems because the two need the same name. You also need to change the name in the field what shows the location of the Home directory.
Open System Preferences > Users & Groups.
Click unlock and enter the password for the admin account you just logged in with.
From the list of users, Control-click or right-click the user that you want to rename.
Select Advanced Options.
Change Account Name field to the new name you just gave the Home folder for that user.
Next change the Home directory field to match the new name you gave the Home folder.
Close System Preferences.
Restart the Mac.
Log on to the renamed account
If you have any problems logging in check that the account and one directory names are the same.