The Department told us it has a lengthy and comprehensive training course for caseworkers followed by mentoring to ensure that caseworkers formulate awards accurately.63 The National Audit Office noted that, as of March 2021, the Department was aware of six overpayments, totalling £38,292 in value.64 Based on a review of a small 49 C&AG’s Report para 2.7 50 Qq 46–48 51 Qq 47–48 52 Q 46 53 Q 46 54 Q 29 55 C&AG’s Report, para 4.4 56 Q 31 57 Qq 29, 31, 55 58 Q 52, C&AG’s Report, para 4.3 59 Q 52 60 C&AG’s Report, para 4.3 61 Q 30 62 Qq 66–68 63 Q 54 64 C&AG’s Report, para 4.17 12 Windrush Compensation Scheme sample of casework, the National Audit Office found that the Department’s quality assurance processes are not picking up all errors.65 It also reported that the scheme’s quality assurance managers return more than half of claims they review to a caseworker for further work.66 The Department said that this was sometimes because not everything had been done to maximise compensation for the claimant, but acknowledged it wants to reduce the number of cases returned to caseworkers.67 The Department told us it is reviewing its guidance and processes for its relatively junior caseworkers to make them simpler and reduce the risk of making errors.68