It is difficult for Parliament and the public to be assured that HMRC settles large and long-running tax disputes fairly and consistently, given it reports only a limited amount of the testing that it carries out. HMRC reports the results of its tax assurance settlement programme each year to Parliament. However, in 2024–25 this programme only examined 20 disputes involving large businesses. Though HMRC does carry out other testing, it does not publicly report these results. HMRC could not provide us with assurance over long-running tax disputes, even where the details of these disputes are freely available in the public domain. The limited nature of HMRC’s reporting does not help to change public perceptions that large businesses play by different rules to other taxpayers. While we recognise HMRC has a duty to protect taxpayer confidentiality, it is frustrating that HMRC is not doing more to reassure Parliament and the public that it is acting fairly and consistently in such cases. recommendation Building on recent recommendations we have made to HMRC on improving transparency and publicising its successes to deter egregious behaviour, HMRC should report back on how it plans to improve assurance to Parliament and the public on: a. the scale and outcomes of the testing it carries out on large-business tax disputes; 4 b. the broader themes arising from these large disputes and the implications for other large businesses and HMRC; and c. the successes and outcomes of its compliance work with large businesses.