Given the uncertainties in HMRC’s current estimates of error and fraud in R&D relief claims, we asked HMRC what it was doing to improve its estimates. It told us that it was planning a random enquiry programme for R&D claims which will inform its estimate. We expressed our concerns that HMRC was not on top of the abuse problem. HMRC said that it had increased the resources it deployed on R&D compliance. Referring to Budget 2021 and a November 2021 HM Treasury report on R&D tax reliefs published 24 HMRC, National statistics, Research and Development Tax Credits Statistics: Updated 30 September 2021, section 10 and HM Treasury, R&D Tax Reliefs – Report, November 2021, para 1.6 25 C&AG’s Report, 4.32, 4.34–4.35, 4.37 26 Qq 133–135 HMRC Performance in 2020–21 13 the day before our evidence session, HMRC said that it had been advising Ministers about the extent to which it could control abuse operationally through its compliance response, and whether policy changes may be required to R&D reliefs. HM Treasury’s report set out the government’s plans to target abuse of R&D reliefs and improve compliance.27 Tax compliance