European Court of Auditors Annual Report on the implementation of the budget for 2011

Every year the European Court of Auditors is auditing the revenue and expenditure of the EU budget and provides its opinion on the extent to which the annual accounts are reliable and income and spending transactions comply with the applicable rules and regulations.

Ensuring that the budget is properly spent is primarily the responsibility of the European Commission, along with the other EU institutions and bodies. But for around two-thirds of spending – principally natural resources and cohesion – this responsibility is shared with the Member States.

The auditors test samples of transactions to provide statistically-based estimates of the extent to which revenue and the different spending areas (groups of policy areas) are affected by error.