Use Protect Sheet on the Review tab to stop edits to one worksheet: tick what others may still change, then set a password. If the goal is keeping people out of the whole file, that's a different tool, Encrypt with Password, found under File. Decide based on whether you're guarding against edits or against prying eyes.
Picture a team rota or a planning template you share around the office. You want colleagues filling in their own rows without wiping out the formulas you spent an afternoon building. That's a sheet protection job. A workbook holding salaries or client details that only you should open is an encryption job. Different problems, different settings.
Leaving some cells editable before you lock the sheet
Microsoft treats sheet protection as two steps: choose the cells people may still edit, then switch protection on. Skip the first step and you'll find the cells you meant to leave open are shut along with everything else.
- Select the cells others should fill in.
- Right-click and choose Format Cells.
- Open the Protection tab.
- Clear the Locked box.
Those cells stay editable once the sheet is protected. On a rota, that might be the column where people type their initials, while the dates and totals stay fixed. On an expenses template, it could be the amount and description columns, with the formulas that add them up left locked.
A quick test once protection is on: try typing in a locked cell and in one you cleared. If both accept your typing, the sheet isn't protected yet. If neither does, the Locked box is still ticked on the cells you meant to free, so go back to Format Cells and clear it.
Locking one worksheet with a password
- Go to the Review tab.
- Select Protect Sheet.
- Work through the list headed Allow all users of this worksheet to.
- Add a password if you want one.
That password is what gives the lock its teeth. It has to be typed before anyone can take the protection off again. If you ever need to reverse it yourself, there's a separate walkthrough on removing protection from a sheet.
Set your expectations, though. Microsoft's page on protecting a worksheet is clear that this isn't meant as a security measure. It blocks changes to locked cells and that's all, so think of it as guard rails for well-meaning colleagues rather than a safe for private data.
The allow list is where you fine-tune the lock. Tick only the actions colleagues need for their part of the job and leave the rest unticked. It's easier to loosen a rule later than to repair a formula someone overwrote.
Protecting a sheet without any password
The password is optional. Microsoft describes sheet protection as something you can switch on with or without one. Leave it blank and the locked cells still resist accidental typing, but nothing stops another person switching the protection off, because the password is the part that guards against that. It suits a sheet where you only want to stop slips, not deliberate changes.
A handy case is your own template. If you're the only person who uses it, a password just adds something to remember, while protection without one still stops you typing over a formula by mistake on a busy day.
Encrypting the whole workbook so it won't open
- Select File, then Info.
- Open the Protect Workbook box.
- Choose Encrypt with Password.
- Type a password and select OK.
- Retype it in Reenter Password, then OK.
From then on, opening the file means typing that password first. Capitals count, so Rota2026 and rota2026 are two different passwords. If you're securing a report alongside the spreadsheet, here's how to password-protect a Word document too.
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Test it before you share anything. Close the workbook, reopen it, and make sure the prompt appears and your password gets you in.
What a password here won't do for you
The hardest limit first: Microsoft has no way of recovering a forgotten file password. Lose it and Microsoft can't get it back for you. Store it in a password manager or somewhere equally safe before you close the file.
Encryption isn't bulletproof either. According to Microsoft's guidance on protecting an Excel file, putting a password on a workbook isn't guaranteed to keep out someone with malicious intent.
Frequently asked questions
Can I use both protections on one workbook?
Yes. Encrypt the file so only trusted people can open it, then protect individual sheets so they can't overwrite formulas by accident.
Can a file password be long or include symbols?
Yes. Microsoft sets no length or character restrictions, though capitals still count.
Does a protected sheet stop people opening the file?
It doesn't. The sheet lock only blocks edits to locked cells, so the workbook still opens for whoever has it. For a file nobody can open without typing a password, encrypt it from File > Info.
Is Protect Sheet the same as Protect Workbook?
No, though the similar names are easy to mix up.Protect Sheet guards edits on a single tab, while the Protect Workbook box is the route to encrypting the entire file.
Do cells I never touched stay locked?
Yes. Clearing Locked is something you do only for the cells people should edit, so everything you leave alone is shut once protection goes on.
