How to Password Protect an Excel File

It's a good practice to password protect an Excel file if you store a lot of sensitive data in it.

There are several ways to secure an Excel workbook. You can apply security so no one can open the file without a password, or you can set it up so no one can change anything in the file without a password but can open it as read-only.

How to Set a Document-Open Password in Excel

To configure your workbook so no one can open it without a password, apply a document-open password in the Info area of Excel.

1. With the workbook open, select File > Info > Protect Password. Select the Protect Workbook drop-down menu, then select Encrypt with Password.

2. Enter a strong password in the pop-up window and select OK.

   Remember the password is case sensitive, so you can vary capital and lower case letter to make the password even more secure.

3. Reenter the password, typing it exactly as you did it in the first window. Then, select OK.

   Having to enter the password twice ensures that if you mistype it either time, you won't end up locking the sheet with the wrong password.

4. Once you're done, you'll see the Protect Workbook option change color, with a status indicating that a password is required to open the workbook.

   Your workbook is now protected from anyone opening it if they don't know the password. 

5. When anyone tries to open the worksheet, they see a pop-up window asking for the password.

   If they enter the password incorrectly, Excel lets them attempt to enter it a second time. If they fail to enter the correct password again, the worksheet won't open. This is the best method to secure your Excel files.

How to Add a Modify Password to Your Excel Workbook

Another approach to protecting an Excel worksheet is to apply a password to prevent people from making changes to it after it is open. It becomes read-only for anyone without the password.

1. With your worksheet open, select File > Save As. Then, select Browse to open the file browse window.

2. In the Save As window, select Tools and choose General Options in the drop-down menu.

3. In the General Options window, type a password into the Password to modify field.

   You can also enter a password into the Password to open field, which would require a password to open the workbook at all. This works just like the Info password protection described above.

4. You are prompted to reenter the password beneath Reenter password to modify to make sure you didn't type it incorrectly. Select OK to close the confirmation window and Save.

   To remove modify password protection, just follow the same procedure as above, but clear the password field and select OK.

5. When anyone opens this workbook, they are prompted to enter the correct password to modify the workbook, or they can select Read-Only to open the workbook in read-only mode.

   Using read-only worksheet protection is a smart way to share important information with people while preventing them from changing or modifying a sheet that you worked hard to develop. This is useful for sending reports with complex calculations and formulas.

How to Protect Password Structure During Review

If you frequently review draft workbooks that people create, password protecting the workbook when it's in the review phase is a good way to prevent changes during a quality review.

This doesn't prevent content changes, but it does prevent people from adding, removing, renaming, or creating new sheets. It protects the structure of the workbook itself, rather than the contents.

1. With the workbook open, select Review > Protect Workbook.

2. Type a password and then select OK. You are prompted to enter the password again.

3. Once enabled, when anyone opens this workbook and right-clicks the sheet, all the options to modify the sheet or add new sheets are disabled.