This Committee has regularly examined HMRC’s customer service performance. In 2010, this Committee concluded HMRC’s performance in responding to calls had been poor.43 In 2016, the Committee found that customer service levels had collapsed as a result of HMRC assuming two new services, automated telephony and paperless self- assessment, would reduce the number of calls it received. HMRC released 5,600 staff, but phone demand did not fall and consequently its service levels collapsed.44 HMRC’s performance subsequently improved and in 2017–18 it achieved six of its eight customer service targets.45 Since then, HMRC’s performance has declined. In particular, its performance in answering calls and responding to post in 2020–21 was well below the levels in each of the three previous years. By the last quarter of 2020–21, the average time callers spent queuing to speak to an adviser was over 15 minutes (compared to less than 5 in 2017–18) and just 43% of post was responded to in 15 days (81% in 2017–18).46