Excel: how to protect a sheet so cells cannot be changed

Protecting a sheet stops people accidentally overwriting formulas or headings. It is great for forms and shared workbooks. It is not strong security, so do not use it to hide private information.

How protection works

Every cell in Excel is 'locked' by default, but the lock does nothing until you protect the sheet. So the usual approach is to unlock the cells people are allowed to edit, then switch protection on.

Step 1: unlock the cells people may edit

1. Select the cells that should stay editable, such as input boxes.
2. Press Ctrl+1 to open Format Cells.
3. Click the Protection tab.
4. Untick Locked and click OK.

Step 2: protect the sheet

1. Click the Review tab.
2. Click Protect Sheet.
3. Type a password if you want one. It is optional.
4. Choose what people can still do, such as selecting cells or formatting columns.
5. Click OK, and retype the password if asked.

Anyone who tries to change a locked cell now sees a message saying the cell is protected.

Remove protection

Click Review, then Unprotect Sheet, and enter the password if there is one.

Protect the whole workbook

• Protect Workbook on the Review tab stops people adding, deleting or renaming sheets.
• To make people enter a password before even opening a file, choose File, Info, Protect Workbook, Encrypt with Password.

Important warnings

• Write the password down somewhere safe. If you lose a file's open password it is very hard to recover, and Microsoft cannot help.
• Sheet protection can be got around by a determined person. Treat it as a safeguard against mistakes, not a lock on a safe.
• Do not use your email or banking password.

Common problems

• I cannot edit anything: you have probably forgotten to unlock the cells in step 1.
• Some buttons are greyed out: the sheet is protected. Unprotect it first.
• Macs: the Review tab has the same buttons.

When to get more help

If you are locked out of an important spreadsheet, contact us as soon as possible, and avoid downloading password-cracking tools from the internet.