voorlopige aanslag

A provisional tax assessment is an advance tax bill that the Belastingdienst (Dutch Tax Administration) issues before the final figures are known. It is based on the tax rules in force and the income and details it already has, and it is later settled against the definitive assessment after the annual tax return. Because it is set in advance, the rules for the coming year must be in place before the Belastingdienst can calculate these bills.