How to Lock Cells in Excel

Prevent unauthorized changes to data by protecting worksheets. In a protected worksheet, none of its contents can be changed. However, it’s possible to set up the worksheet so that only certain cells and elements can be changed after it's protected.

Lock or Unlock Cells

By default, cells are locked once a worksheet is protected. If there are cells that users should be able to change after a worksheet has been protected, make sure to unlock them before you protect the worksheet.

1. Select the cells you want to unlock.
2. Click the Format button on the Home tab.
3. Select Format Cells.
   
4. Click the Protection tab.
5. Clear the Locked check box.

   You can also toggle the lock on and off by clicking the Format button and selecting Lock Cell.

   Locking and unlocking cells only takes effect once the sheet is protected.

6. Click OK.
   

The selected cells will now stay unlocked and editable by others after the sheet is protected.

Hide Formulas

You can also prevent certain formulas from being displayed once the worksheet has been protected.

1. Select the cells with a formula you want to hide.
2. Click the Format button on the Home tab.
3. Select Format Cells.
   
4. Select the Hidden check box.
5. Click OK.
   

Remember, even if cells are locked and hidden, it doesn’t take effect until the worksheet is protected.

Protect a Worksheet

Once you finish preparing the worksheet, it’s time to protect it.

1. Click the Review tab.
2. If necessary, expand the Protect group.
3. Click the Protect Sheet button.
   

   You can protect or unprotect a worksheet by right-clicking the sheet tab and selecting Protect Sheet or Unprotect Sheet from the contextual menu.

4. Select what you want to protect.

   A password isn’t necessary to protect the sheet; however, if one is not entered, anyone can unprotect it.

5. Click OK.