How to Protect Excel Worksheet?
The purpose of protecting Excel worksheets is to either prevent unauthorized users from accessing the file or to make only certain sheets/cells editable.
Protect Excel Worksheet Data: Encrypt with Password
Excel provides various tools to prevent accidental changes to the data contained within a file.
If you’re working with confidential data, it is critical for the file to be encrypted with a password.
Otherwise, a file that is not password-protected is far more vulnerable to security breaches or mistakes (e.g. sending a file to the wrong recipient), which could even lead to legal repercussions.
As such, it is standard practice for all files with confidential client data to be password-protected with the password then only circulated among the right parties.
For example, PDFs containing the financial statements of a private company in an M&A process and a firm’s internal financial model using such data must be password-protected.
To password protect a file, the following shortcuts in Excel can be used to open the “Info” page.
Open Info Page: Alt → F → I
Next, by clicking on “Encrypt with Password”, the pop-up box with the form to enter a desired password should appear.
Once entered, the entire file cannot be opened without entering the correct password first.
Protect Excel Worksheet Data: Protect Current Sheet
Another option in Excel is to prevent editing on certain sheets, which can be done by clicking on “Protect Current Sheet” from the previous “Info” page.
As shown in the screenshot below, there are multiple toggles that can customize what the viewer can (and cannot) do:
Alternatively, the following keys can open the same popup box, but through the ribbon at the top.
Open Review Tab in Ribbon: ALT → R
There are multiple options from this point, but two of the main ones are:
ALT → R → PS: Protects the current sheet that is open on the screen.
ALT → R → PW: Protects the entire workbook.
Protect Excel Worksheet Data: Protect Cells/Ranges in Excel
There can be occasions when you may want to prevent specific cells from being modified but still allow the viewer to adjust other surrounding cells.
To specify which certain cell should be locked (or unlocked), “CTRL → 1” can be clicked to open the format properties.
The final column “Protection” gives the option to select whether to lock the cell or not.
Alternatively, a group of cells can be named and password protected.
Either “Allow Edit Ranges” from the ribbon or “ALT → R → U1” can be used to open up the following screen.
If “New” is pressed, the option is given to select the specific cell or range of cells to protect.
In effect, the viewer cannot edit the range of cells chosen without first entering the correct password, but can still freely make changes to any non-protected cells.