There are around 30 different types of benefits and pensions, and £148 billion was paid out to 20 million people in 2009-10. The Department for Work and Pensions estimates that £2.2 billion of overpayments and £1.3 billion of underpayments were made in 2009-10 as a result of administrative errors by its staff and mistakes by customers. Efforts to tackle error have had little success and levels of error have remained constant since 2007. A joint HM Revenue and Customs and Department for Work and Pensions fraud and error strategy announced in October 2010, along with additional funding of £425 million over four years, is an opportunity to inject a new impetus. Importantly, the Department has not addressed underpayments, despite the hardship that benefit underpayments can create for people in need. Interventions to reduce error must be targeted where they are most likely to get the greatest return. Progress on reducing error requires a better understanding of where and why errors arise, and a greater focus on preventing errors occurring in the first place. The Department is not making use of all available sources of information to identify the reasons why staff make mistakes, where guidance and training efforts should be directed, and to identify which customers are most likely to make mistakes on their benefit claims. Wider welfare reforms have the potential to reduce errors in the long term by simplifying benefits administration, but waiting for the implementation of the Universal Credit is not an option.