Thank you very much for your help and I hope you excuse my basic English as well!

I've been working on the sheet lately and I've managed to make it work.

I created a tab called Datos which displays the data from the pivot table so I can use it to fill the form.
The only issue is that when I click on Proveedores the following message appears highlighting this line: 

' Refresh the pivot tables
shtP.PivotTables("Pt_referencia").PivotCache.Refresh
Run-time error 1004. We couldn't complete the action for PivotTable" PT_proveedor" in "pivot" because there's already a PivotTable"Pt_referencia" there. Make space and try again.


Still works though but I can't get rid of the message.

COSTES FINAL filter merma v2 macro.xlsb