Use Touch ID on your Mac
If your Mac has a Touch Bar, you can use Touch ID to unlock your Mac and some password-protected items, use Apple Pay to make purchases on the web, and make purchases from the iTunes Store, App Store, and iBooks Store.
Set up Touch ID
Choose Apple menu > System Preferences, then click Touch ID.
Click “Add a fingerprint,” enter your password, then follow the onscreen instructions.
You can add up to three fingerprints to your user account (your Mac can store up to five fingerprints total).
Click the checkboxes to select how you want to use Touch ID:
Unlocking your Mac: Use Touch ID to unlock this Mac when you wake it from sleep.
Apple Pay: Use Touch ID to complete purchases you make on this Mac using Apple Pay.
iTunes & App Store: Use Touch ID to complete purchases you make on this Mac from the Apple online stores.
Rename and delete fingerprints
Rename a fingerprint: Choose Apple menu > System Preferences, then click Touch ID. Click the text below a fingerprint, then enter a name.
Delete a fingerprint: Choose Apple menu > System Preferences, then click Touch ID. Click a fingerprint, enter your password, then click Delete.
Use Touch ID
Important: To use Touch ID for the following tasks, you must have logged in to the Mac already by entering your password.
Unlock your Mac and some password-protected items: When you wake your Mac from sleep, or open a password-protected item, just place your finger on Touch ID when prompted.
Purchase items: When you buy an item using Apple Pay, or from one of the online Apple stores, place your finger on Touch ID when prompted.
Switch users: Click the fast user switching menu in the menu bar, choose a different user, then place your finger on Touch ID.
To use Touch ID to switch to another user, you need to have set up fast user switching, and the user you switch to must have logged in to the Mac already by entering a password.
Log in from the login window: Click your name in the login window, then place your finger on Touch ID.
Only user accounts that have passwords can be unlocked with Touch ID. Share-only users and guest accounts cannot use Touch ID.
If Touch ID doesn’t recognize your fingerprint, make sure your finger is clean and dry, then try again. Moisture, lotions, cuts, or dry skin can affect fingerprint recognition.
Sometimes you’ll need to enter your password to continue using Touch ID. For example, users must re-enter their password every 48 hours and after five incorrect fingerprint attempts.
Note: For added security, only logged-in users can access their own Touch ID information; an administrator cannot change another user’s Touch ID preferences or fingerprints.