This article examines the issue of benefits overpayments in UK social security law. Current estimates put the level of overpayments due to error (as opposed to fraud) at about £2 billion per annum. Concern about his issue has led to the publication of a DWP statement of strategy and an attempt by DWP to use the common law to recover overpaid benefits. The article looks at a number of recent court decisions which have important implications for UK practice.