HMRC is taking too long to resolve compliance investigations and bring in the taxes owed by large businesses. The investigations into large businesses that completed in 2024–25 took on average 17 months to conclude. This is down from the high of 35 months for cases completed in 2021–22, following the COVID-19 pandemic, but represents only a slight reduction from 2019–20 levels. Investigations involving litigation are taking much longer, with an average case duration of 97 months in 2024–25, up from 57 months in 2019–20. In response, HMRC is increasingly using alternative dispute resolution to avoid the lengthy litigation process, it claims that this is already reducing the number of cases going through litigation. Where litigation is required, HMRC says it will focus on ensuring that cases are better prepared before they go to court, where it already has a 90% success rate. recommendation In its Treasury Minute response, HMRC should set out what more it will do to accelerate the time taken to resolve compliance investigations, in particular those where the business decides to litigate.