This report presents the results of applying the RA-GAP VAT gap estimation methodology to Belgium for the period 2011-2021. The Revenue Administration Gap Analysis Program (RAGAP) methodology employs a top-down approach for estimating the potential Value-Added Tax (VAT) base, using statistical data on value-added generated in each sector. There are two main components to this methodology for estimating the VAT gap: 1) estimate the potential VAT collections for a given period; and 2) determine the accrued VAT collections for that period. The difference between the two values is the VAT gap.