How to Protect Your Excel Documents

March 21, 2017

Considering the fact that Microsoft Excel documents are often used to process and share sensitive numbers and data, it’s important to be familiar with some of the options that are available to protect your documents from being viewed or altered by others. And, even security aside, there’s nothing worse than somebody accidentally ruining your Excel doc.

To help you avoid both intentional and accidental malfeasance, here are three quick tips for safeguarding your Excel files:

Lock Your Cells

One easy way to prevent accidental changes to your spreadsheet is to lock its cells. To do so, go to the Review ribbon and choose Protect Sheet.

In the window that opens, make sure Protect Worksheet and Contents of Locked cells is checked. Then click OK.

This locks all the cells in the sheet, preventing any changes from being made to them. If you or anyone else tries to alter the contents of a cell, a message pops up telling you that the spreadsheet is protected.

However, it’s possible that you’ll want to keep some of the cells unlocked so you can make changes, while keeping the rest of the cells locked. For example, if you have a worksheet set up to automatically calculate the cost of certain items, you may want to keep the cells with the per-unit prices locked while leaving the cells where you enter the quantity of items unlocked.

To do this, first uncheck the Unprotect Sheet button. Then select the cells you want to unlock. Under the Home ribbon, click the Font Settings button, go to the Protection tab, and uncheck the Locked checkbox. Click OK and return to the Review tab, and click Protect Sheet again.

Once more, make sure Protect Worksheet and Contents of Locked cells is checked. (If you want to prevent this protection from being turned off by someone else, you can create and enter a password here.) Once you click OK, the content of your selected cells can be changed, while the rest of the cells remain locked and protected.

Password Protect an Entire Workbook

There will be times when you’ll want to prevent unauthorized people from even opening some of your Excel files. You can easily protect an entire workbook by adding a password to it.

To do so, open the file in Excel and select File > Info. Click the Protect Workbook button, and select Encrypt with Password.

Enter a password of your choosing. There are no restrictions on the length or type of characters you can use, but note that passwords are case-sensitive.

Once you’ve entered a password, click Ok and confirm the password by typing it again.

After you close the workbook, the next time you or anyone else opens it, a prompt to enter the password will appear. Entering the correct password is now the only way anyone will be able to access the contents of the workbook, and there is no method to recover the password or to open the file in another way, so be sure not to forget the password.

Once the correct password is entered, you’ll have complete access to the file, just like any other file in Excel.

Restrict Access

There will also be times when you’ll want to password protect a workbook to allow only certain people to open it, but you may not want some of these authorized users to be able to change any of the content of the file. Excel allows you to set up passwords to both open the file and to alter the file.

Start by opening the file, and then choosing File > Save As. In the Save As window, click the Tools menu and choose General Options.

In the window that opens, you can apply a password to open the workbook, and a password to modify the workbook. If you want to restrict viewing of the workbook to only authorized users, enter a password for Password to open.

Note that you can leave this field blank if you want anyone to be able to open the file.

To prevent users from modifying the workbook, enter a Password to Modify. Click OK and then confirm your password or passwords. As always, be sure to remember your passwords.

Save and close the workbook. When it’s next opened, if you applied an Open password, users will be prompted to enter that password in order to view the workbook. Next, they’ll be prompted to enter the Password to Modify, if you created one, or they can click Read Only if they don’t have that password.

Without the modify password, they’ll only be able to view the workbook, but not make any changes, while users with the modify password will have complete access to edit or alter the contents of the workbook.

Want to fully unlock the power of Microsoft Excel? Check out all of our LinkedIn Learning courses on the topic.