Legal provision for the establishment and operation of the AA:
COMMISSION REGULATION (EC) No 718/2007 of 12 June 2007 implementing Council Regulation (EC) No 1085/2006 establishing an instrument for pre-accession assistance (IPA)
Article 102 - Designation of authorities
Article 105 - Functions of the audit authority

The Audit Authority for the programme is the Audit of European Union Funds Implementing Agency of the Republic of Bulgaria, and it is assisted by a Group of Auditors.

The Audit Authority is functionally independent of the Managing Authority and the Certifying Authority and is responsible for:

• ensuring that audits are carried out to verify the effective functioning of the management and control system of the cross-border programme;
• ensuring that audits are carried out on operations on the basis of an appropriate sample to verify expenditure declared;
• by 31 December each year from the year following the adoption of the cross-border programme to the fourth year following the last budgetary commitment: submitting to the Commission an annual control report setting out the findings of the audits carried out during the previous 12 month period ending on 30 June of the year concerned and reporting any shortcomings found in the systems for the management and control of the programme; issuing an opinion, on the basis of the controls and audits that have been carried out under its responsibility, as to whether the management and control system functions effectively, so as to provide a reasonable assurance that statements of expenditure presented to the Commission are correct and as a consequence reasonable assurance that the underlying transactions are legal and regular
• submitting to the Commission at the latest by 31 December of the fifth year following the last budgetary commitment a closure declaration assessing the validity of the application for payment of the final balance and the legality and regularity of the underlying transactions covered by the final statement of expenditure, which shall be supported by a final control report. This closure declaration shall be based on all the audit work carried out by or under the responsibility of the audit authority.
• ensuring that the audit work takes account of internationally accepted audit standards;
• where the audits and controls referred to in first two bullets are carried out by a body other than the audit authority, the audit authority shall ensure that such bodies have the necessary functional independence professional proficiency to perform the tasks according the international accepted audit standards and the relevant EU and Bulgarian legislation.
• giving the reasons and estimating the scale of the problem and its financial impact in the case described in Article 105 (4);
• designating the Bulgarian experts in the group of auditors and carrying out training of all members of the group.
• an audit strategy for the whole programming period will be elaborated by the AA
• preparing compliance assessment report on the management and control systems.