You can drill down in the VAT transactions report and change the nominal in a tx. Rerun the report and it does not change the nominal. You have to recalculate the VAT return before the nominal is changed. Also, you can change the values in a tx. If you do this from drilling down into a BP/BR then when you look at the (still open) transaction report again it has disappeared. Again, you have to recalculate the return before it shows on the report again.