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.

Sending Excel files containing crucial financial and business data has risks. To add a layer of protection, you should learn to password protect an Excel file.

There are several options available to you to protect your Excel file with a password. Remember that once you protect the Excel file, you cannot open it without entering the password.

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.

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 ...

You can have Excel make a spreadsheet in read only format for others, so that people can read its contents but not edit them, or you can enforce other content restrictions.