Due to the way it is estimated, the tax gap does not yet reflect the full impact of the pandemic and will not do so for some time. HMRC’s latest estimate is that the tax gap remained stable in 2020–21, at 5.1% of taxes theoretically owed. However, HMRC’s tax gap estimates typically need to be revised over several years as it gets more data. HMRC told us that its 2020–21 estimate has a much larger range of uncertainty than normal, because of the impact the pandemic had on some of the key data sources it uses.39