How to Password Protect an Excel File (and Not Lock Yourself Out)

Client lists, staff rotas, order histories, a business plan you'd rather keep to yourself: plenty of spreadsheets hold things you don't want just anyone opening. Excel can lock the whole file behind a password, so nobody gets past the opening screen without it.

It's a four-step job, but there are two things to understand before you start. First, Microsoft can't get you back in if you forget the password. Second, Excel has three different kinds of protection that sound alike and do very different things. I'll cover both, then the steps.

File, workbook or sheet: which Excel protection do you need?

Microsoft's help is careful to say its password steps cover file-level protection only, not workbook or worksheet protection. Here's the difference in plain terms:

Type of protection	What it stops	Where you set it
File password (encryption)	Anyone opening the file without the password	File, Info, Protect Workbook, Encrypt with Password
Workbook structure	Adding, deleting, moving or renaming sheets	Review tab, Protect Workbook
Worksheet protection	Editing locked cells on one sheet	Review tab, Protect Sheet

If you want to share a file but stop people changing your formulas, sheet protection is the better fit, and my guide on locking specific cells in Excel explains it. If you want the file closed to everyone without the password, read on.

Password protecting an Excel file step by step

These are Microsoft's steps:

1. Open the workbook and select File.
2. Select Info.
3. Select the Protect Workbook box and choose Encrypt with Password.
4. Type your password in the Password box and select OK.
5. Type it again in the Reenter Password box and select OK.
6. Save the file.

The Info page now shows that a password is required to open the workbook. Close it and open it again to check: Excel asks for the password before showing anything.

Choosing a password for your Excel file

Microsoft says there are no restrictions on length, characters or numbers, but passwords are case-sensitive. So "Summer" and "summer" are two different passwords.

• Use a long phrase rather than a short word. It's easier to remember and harder to guess.
• Store it in a password manager the moment you set it.
• Don't reuse the password you use for email or banking.
• Don't write it in the file name or in a note inside the same folder.

What happens if you forget an Excel file password

This is the part I want every small business owner to hear. Microsoft states plainly that it can't retrieve forgotten passwords. There's no reset link and no support ticket that unlocks the file.

So before you encrypt anything important, keep an unprotected backup somewhere safe, such as an encrypted drive or a secure folder only you can reach, or record the password somewhere reliable. If you're protecting a file for a client or colleague, agree who holds the password before you hand it over.

Sharing a password-protected Excel file safely

Microsoft adds some honest warnings worth taking seriously:

• It isn't always secure to send password-protected files containing very sensitive details, and Microsoft gives card numbers as an example.
• Passwords can fall into the wrong hands once you share them.
• Locking a file with a password doesn't necessarily protect it from someone with bad intentions.

In practice, I send the file by email and the password by a different route, such as a text message or a quick call. Sending both in the same email defeats the point. For anything like card or identity details, don't keep them in a spreadsheet at all.

When a file password makes sense for small businesses

I'd use file encryption for anything that would cause real trouble if it went astray: a customer list with phone numbers and addresses, staff details, or a file you keep on a laptop that travels with you. A lost laptop with a locked workbook is a much smaller problem than one with an open file on the desktop.

For day-to-day team files, a password on every workbook quickly becomes a nuisance, and people start writing passwords down. In those cases, storing the file somewhere with sensible access controls and using sheet protection for formulas is usually the calmer option.

Removing the password from an Excel file

If you no longer need the lock, open the file with the password, then go back to File, Info, Protect Workbook, Encrypt with Password. Clear the password box, select OK and save. The next time you open the file, Excel won't ask.

You need the current password to do this. If someone else set it and you don't have it, ask them, because Microsoft can't help.

Password protecting Excel on a Mac and other versions

Microsoft's article lists Excel for Mac among the versions it applies to, alongside Excel for Windows. Menus vary between versions, so if you can't see File, Info on your Mac, look for password options in the Review tab or in the file's save options. Whatever the route, the same rules apply: passwords are case-sensitive and can't be recovered by Microsoft.

If Excel won't let you add a password

• Encrypt with Password is missing: you might be in Excel for the web or a mobile app. Open the file in the desktop app.
• The option is greyed out: the file may be shared or co-authored live. Stop sharing, add the password, then share again.
• The password doesn't work: check Caps Lock. Microsoft says passwords are case-sensitive.
• You protected a sheet, not the file: Protect Sheet only stops edits. Use Encrypt with Password to lock the whole file, and see how to unprotect an Excel sheet if you need to undo sheet protection.

Frequently asked questions

How do I password protect an Excel file?

Go to File, Info, select Protect Workbook and choose Encrypt with Password. Enter a password, select OK, enter it again and select OK, then save the file.

Can Microsoft recover a forgotten Excel password?

No. Microsoft says it can't retrieve forgotten passwords, so keep a safe backup or store the password somewhere reliable.

Are Excel file passwords case-sensitive?

Yes. Microsoft says there are no length or character restrictions, but passwords are case-sensitive.

What's the difference between protecting a file and protecting a sheet?

A file password stops anyone opening the workbook. Sheet protection lets people open it but stops them editing locked cells.

Is a password-protected Excel file completely secure?

Not entirely. Microsoft warns that a password doesn't necessarily protect a file from malicious intent and advises caution with very sensitive data.