The National Audit Office continues the budgetary control traditions of the Supreme Chamber of Control, which was established by law in 1880 and was operating until 1947.
Art. 91 of the Constitution of the Republic of Bulgaria says as follows:
(1) The National Assembly shall establish a National Audit Office to supervise the implementation of the budget.
(2) The organization, authority and procedures by which the National Audit Office shall act shall be established by law.
According to the new National Audit Office Act adopted in December 2010, the NAO comprises a president and two vice-presidents elected by the National Assembly.
The NAO exercises control over the implementation of the budget and other public funds and activities in accordance with the NAO Act and the internationally accepted auditing standards.
The main task of the National Audit Office is to control the reliability and truthfulness of the financial statements of budget-funded organisations, the legality, efficiency, effectiveness and economy of the management of public funds and activities, as well as to provide the National Assembly with reliable information thereof.
The National Audit Office is independent in performing its operations and reports directly to the National Assembly.
The operations of the National Audit Office are performed on the basis of the following principles:
1. independence, objectivity and good faith;
2. professionalism, integrity and impartiality;
3. consistency and predictability;
4. openness and transparency;
5. trust, co-operation and constructiveness.
The NAO has an independent budget, which is part of the republican budget of the Republic of Bulgaria.
The NAO adopts an annual audit program. The National Assembly can, by virtue of its decision, assign to the National Audit Office to carry out up to five audits a year outside the audits envisaged in the annual programme.