If you have sensitive data you'd like to keep from prying eyes in a Microsoft Excel file, the easiest way to protect it is with Excel's built-in password tools.

If you want to set an expiration date and password when sharing Excel files online, here is how you can do that. It is possible to do both of them when using Excel Online.

You can add or remove a password from your Excel spreadsheets through the File tab. You'll do it slightly differently on a Mac and PC.

In Word, Excel, or PowerPoint for Windows, open the file you want to protect with a password, then select File and Info. You should see a Protect option at the top of the next list: Click this ...