A password set on a Numbers spreadsheet has no effect. Why?

Your keychain has remembered your password, so it's inputting it for you and allowing you to open the file without a tying in the password. Open keychain access and search for the specific document. Double click in the name and check the box for "show password" and delete the password in the form. When prompted, click save changes. Close out and try reopening your document, you should now be asked for your password when opening the document, since keychain no longer has the password saved. Just don't check the box for it to remember the password if you want to continue entering it manually every time on your computer.

When you check that little box asking if you want to remember this password in your keychain, you will not be prompted for a document password in your user account — because keychain automatically supplies it without any password prompt. Once the document is in another user account, or off your Mac entirely, there will always be a password prompt to open it.

Did you lock the file in the "Finder"? If so, you have only prevented the file from being modified, or deleted. To set a password on a Numbers document, select the menu item (while in the application Numbers) "File > Set Password..."

A note of caution... as we have seen many requests in this forum about recovering or otherwise getting around a password when a user forgot the password... When you set a password on a Numbers file:

- the good news is that Numbers will require a password to open the file

- the bad news is that Numbers will require a password to open the file

If you forget the password the contents of the numbers document is not recoverable. You should do this very carefully. You may also want to back up before setting the password.

There is not a problem with Numbers with regard to passwords. It's just that it works.