The structure of VAT Gap. The VAT gap consists of 2 main components - unidentified VAT and collection gap. The unidentified VAT is comprises undeclared VAT not identified by FASR within tax audits. It is defined as the difference between the potential and the declared VAT revenue. The collection gap is defined as the difference between the declared and the actually collected VAT. Besides others it also contains the VAT assessed within tax audits and not paid by audited tax payers.