Can you lock one filter in a pivot table?

[Ray707]

Then your cause is lost.
Anyone with a little nous can do some internet searching and break any protections on the workbook, then they can create their own pivot from the data.
Can't you restrict the data to just the relevant departments? I realise this might mean some measures or calculated items/fields might not show correctly if they use company-wide data.

Interesting. So when there is source data in the file there is no way around this? Damnnit

I'll delve deeper into some of your solutions outlined above. Thanks for your help!