HMRC’s 2020–21 estimates of the tax gap are more uncertain than usual due to the impact of COVID-19 on the data it uses to inform its estimates. For example, HMRC said it has had to make some assumptions about the underlying level of write-offs and remissions that might happen. HMRC does not publish an overall range around the tax gap at the moment, and said it was quite difficult to do given the different methodologies used to calculate the tax gap for each individual component. In its reporting, HMRC comments on the confidence it has in each of these components, and sets out the sensitivity associated with any assumptions used. We asked whether HMRC was confident that the tax gap had actually stayed the same in 2020–21. HMRC said that it was confident that the 2020–21 estimate is the best possible estimate at the moment given the data available.12 6 C&AG’s report, para 1.25 7 Qq 24–29 8 Qq 13–14 9 C&AG’s report, para 5 10 Q 15 11 Q 46 12 Qq 15, 19–23; C&AG’s report, para 5 HMRC performance in 2021–22 11