it's for the civil part. (so you need to show the tax office some paper trail that you based your filings on. invoices, bills, contracts, emails, receipts. and if they are formally okay, then the tax agency has to show that they are just fake papers.)
as far as I understand the criminal part still considers intent and so on (and has a higher standard for burden of proof), but if you file for VAT return and then you have zero invoices (and so the numbers simply don't add up) the court can easily find that there was intent to defraud the state. (and then sentencing is based on the amount of damages.)
