1. Wrong VAT return filing because of an error with the data:

• In case of audit, the VAT payable amount might be higher than reported. If higher, there is a penalty + interests for the late payment. Penalty of 20 % from the calculated tax by the Tax authority is imposed + interest according to the current REPO rate set by CZech National Bank.
•  The interests are 0,05% for each day of the delay in case of the late submission of the VAT return. 

2. Wrong VAT return filing done with the purpose of hiding transactions or similar:

A false VAT declaration is considered by the Tax Authorities as a serious case of bad faith or even fraud. This can lead to heavy financial penalties or jail depending on the amount