VAT crackdown on SMEs nets £4.4bn HMRC collected an extra £4.4bn from SMEs following investigations into the underpayment of VAT last year, up 18% from £3.8bn collected in 2017/18, according to tax investigation insurance firm PFP. The firm said the growth in the "VAT gap", which reached a record high in 2017/18 of £12.5bn, up 13% from £11.1bn the previous year, has resulted in HMRC becoming increasingly aggressive in pursuing underpaid VAT.