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.

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.

At the file level, you can password protect an Excel workbook in two ways: You can determine who can get in and who can save changes.

In Word, Excel, or PowerPoint for Windows, open the file you want to protect with a password, then select File and Info.