Cooperation between the SAIs of the EU Member States and the ECA dates back to the beginning of the Court's existence in 1977. Over the years it has become more organised and institutionalised.
Article 287 of the Treaty on the Functioning of the European Union states that:
"In the Member States the audit shall be carried out in liaison with national audit bodies or, if these do not have the necessary powers, with the competent national departments. The Court of Auditors and the national audit bodies of the Member States shall cooperate in a spirit of trust while maintaining their independence."
Moreover, the Treaty of Nice contains the following declaration:
"The Conference invites the Court of Auditors and the national audit institutions to improve the framework and conditions for cooperation between them, while maintaining the autonomy of each. To that end, the President of the Court of Auditors may set up a contact committee with the chairmen of the national audit institutions."
The large scale decentralisation of the management of the EU budget towards the national authorities in the Member States and beneficiary countries has moved the centre of gravity of the Court's audit towards these countries. Cooperation between the European Court of Auditors and the national audit bodies has therefore developed from a simple legal obligation to a practical necessity dictated by the fact that Community and national administrations have become more closely linked. That is why, in addition to the regular exchanges of information between the SAIs, it has proved necessary to develop the respective institutions' audit approaches to ensure the most effective compliance with international auditing standards.