Financial crimes are increasingly growing in sophistication. Criminals accumulate significant sums through offences including drug traffi cking, fraud, extortion, corruption and tax evasion. Different government agencies may be involved in detecting, investigating and prosecuting these offences and recovering the proceeds of crime. This report describes the current position in 32 countries with respect to the law and practice of domestic interagency co-operation in fi ghting tax crimes and other fi nancial crimes. It outlines the roles of agencies in different countries, existing legal gateways to enable these agencies to share information and other models for inter-agency co-operation. The report identifi es a number of successful practices based on countries’ experiences, and makes recommendations on ways to improve inter-agency co-operation.