You can assign a password to a spreadsheet so only those who know the password can open the spreadsheet. Passwords can consist of almost any combination of numbers, uppercase or lowercase letters, and special keyboard characters.
A spreadsheet can have only one password. If you change an existing password when you share a spreadsheet with others, the new password replaces the original. If you add a password after you share a spreadsheet, be sure to notify participants.
Important: There’s no way to recover your password if you forget it. Be sure to choose a password you won’t forget, or write the password down in a safe place.
If your computer has Touch ID, the fingerprint detection feature, you can use it to open your password-protected spreadsheets with your fingerprint alone.
Choose File > Set Password (from the File menu at the top of your screen), enter the requested information, then click Set Password.
If your computer isn’t set up for Touch ID, “Remember this password in my keychain” appears. You can select the checkbox to add the password to your keychain so you don’t have to type the password each time.
If your computer is set up for Touch ID, "Open with Touch ID” appears. You can select the checkbox to turn on Touch ID for the spreadsheet.
Note: Adding a password to a spreadsheet encrypts the file.
With the spreadsheet open, do one of the following:
Change a password: Choose File > Change Password (from the File menu at the top of your screen). Enter the requested information, then click Change Password.
A spreadsheet can have only one password, so if you change the password when you share the spreadsheet, that becomes the spreadsheet’s only password.
Remove a password: Choose File > Change Password. Type the old password, then click Remove Password.
Before you can use Touch ID to open password-protected spreadsheets, you need to set it up on your computer.
To set up Touch ID, do both of the following:
Set up Touch ID for your Mac: Choose Apple menu > System Preferences, click Touch ID, click “Add a fingerprint,” then follow the onscreen instructions.
Note: If you don’t see Touch ID, this feature isn’t available on your Mac.
Set up Touch ID for Numbers: In Numbers, choose Numbers > Preferences (from the Numbers menu at the top of your screen), then select Use Touch ID.
Double-click the spreadsheet, then place your finger on the right end of the Touch Bar at the top of your keyboard.
If you add a password to a spreadsheet, or change an existing password, it applies only to that version of the spreadsheet and to subsequent versions.
If the spreadsheet is shared, to prevent others from restoring an unprotected version of the spreadsheet or a version with an older password, stop sharing the spreadsheet, add a unique password to it, then share the spreadsheet again.