SME VAT investigations pull in extra £3.75bn HMRC collected an extra £3.75bn from SMEs last year through investigations into the underpayment of VAT, with this total marking a 12% increase on the previous year. PfP says this extra revenue made up half of all revenue collected through investigations into SMEs in 2017/18. It added that VAT receipts, which represent over a fifth of total tax receipts, reached a record high of £125bn last year, up 60% on a decade ago.