DWP estimates that claimants received 1.6% (£4.2 billion) less than they were eligible for in 2023–24, up from 1.5% (£3.5 billion) in 2022–23. These underpayments comprised £1.1 billion in official error and £3.1 billion in unfulfilled eligibility.49 Official error is where a benefit is paid incorrectly due to action, delay or a mistaken assessment by DWP, a local authority or HM Revenue & Customs.50 Unfulfilled eligibility is where a claimant by error, omission or choice fails to provide accurate information or evidence to DWP about their circumstances and as a result receives less than the full amount of benefit they are entitled to. It was referred to as ‘claimant error underpayments’ by DWP until 2023–24.51