Concentrix stopped or amended tax credits awards in 12% of cases investigated, but of these, 32% were overturned after a mandatory reconsideration. Between November 2014 and mid-December 2016, HMRC paid a total of £86,815 in compensation for complaints relating to cases handled by the US firm.

In a report, HMRC’s contract with Concentrix, the National Audit Office uncovered numerous failings in the deal which was terminated last November. The three-year contract, signed in May 2014, was to provide additional capacity and analysis to review and correct personal tax credit payments.

HMRC had estimated that the planned three-year contract would save £1bn from stopping incorrect …