A working spreadsheet can contain cells staff should fill in and formulas they should leave alone. Sheet and range protection can reduce accidental edits, but it is not a way to hide confidential data from people who can access the workbook.

Start with an illustrative copy containing fictitious records. Mark the intended input cells, calculated results and lookup tables. Identify who should maintain the formulas and who only needs to enter new records. A clear layout helps people use the workbook correctly before permissions become involved.

Choose the appropriate editing control

In Google Sheets, open Data, Protect sheets and ranges. Select the intended range or protect a sheet with stated input-cell exceptions. Then choose whether an edit should merely show a warning or whether only specified people should be able to make it.

A warning is advisory: it does not block a confirmed edit. Restricted editing is a different choice. Owners retain their control, and range protection does not create a password-encrypted spreadsheet. Check the actual account roles before assuming your own successful edit represents an ordinary staff member’s access.

Test the normal task and the mistake

Using an authorised test account, enter a harmless value in an allowed input cell and confirm the expected total changes. Then attempt a change in a protected formula cell and observe whether the intended warning or restriction occurs. Check newly added rows as well; a protection range that misses future entries can leave the workbook partly exposed to accidental changes.

Keep private information in a properly access-controlled location. Google explicitly says protection is not a security measure, and hidden tabs can be revealed or accessed through copies. A hidden payroll tab does not become safe to share with the whole team just because it is out of sight.

Once the test works, document which cells people may edit and who maintains the formulas. Recheck the design after expanding the workbook rather than copying yesterday’s assumptions onto new columns.

References: Google Sheets protection.