We asked HMRC what further work it was doing to reduce the time it takes to close its investigations into large businesses. HMRC said that the average case duration is decreasing, and is expected to drop to 16 months once 2025–26 data are finalised, but it recognises that it needs to do more. HMRC told us that it will further speed up investigations by focusing on ensuring cases get the legal and specialist support they need and by ensuring HMRC’s information requests to large businesses are proportionate. It is also exploring whether greater investment into AI and other technologies will help to resolve investigations more quickly. For example, it told us it is using commercially available tools to better extract and analyse huge amounts of the unstructured data it collects from multinationals.26