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 March 2015, the Bulgarian National Audit Office (BNAO) shall consist of a president, two vice-presidents and two members, who shall be elected by the National Assembly.

The BNAO shall carry out control on the implementation of the budget and of other public funds and activities pursuant to this act and the internationally recognized audit standards.

Basic task of the BNAO shall be to control the reliability and accuracy of the financial reports of the budget organizations, the lawful, effective, efficient and economical management of the public funds and activities, as well as to provide to the National Assembly reliable information about this.

The BNAO shall be independent while performing its activity and shall report before the National Assembly.

The activity of the BNAO shall be performed on the basis of the following principles:

1. independence, objectivity and good faith;

2. professionalism, integrity and impartiality;

3. consistency and predictability;

4. publicity and transparency;

5. trust, cooperation and constructiveness.

The Bulgarian National Audit Office shall adopt its annual audit programme. The National assembly may – by its decision – assign to the BNAO to carry out up to 5 audits per year outside the ones, envisaged by the annual programme.

The president, the vice-presidents and the members shall be elected for the term of 7 years. The president may be re-elected. The vice-president shall be elected by the National Assembly upon proposal of the president of the BNAO. The deputy presidents may be re-elected. The National Assembly shall elect upon proposal of the BNAO president one member, proposed by the Institute of the Certified Expert Accountants and one member, proposed by the Institute of Internal Auditors.