The idea to create a legally regulated counterintelligence structure in Bulgaria emerged at the beginning of the 20th century. Both the consolidation of the Bulgarian statehood and the country’s economic growth at the time called for the institutionalization of the security system.

The first legal document arranging the counterintelligence structure is the Capital Municipality Police Act, which was passed by the 13th Ordinary National Assembly, confirmed by Decree № 463 dated 13.12.1906, of King Ferdinand and promulgated in issue 3 of Official State Gazette dated 04.01.1907. In the same Act, the formation of a police structure called "Public safety" was also regulated. The latter operated mainly in the capital, in the big cities and the transportation centers of the country.

A Decree on differentiating the functions of the police-officers and the agents of the Public Safety was adopted in 1912. The Decree defines for the first time the functions of a separate counterintelligence structure and regulates its coordination with the police. 

In the meantime, a specialized military counterintelligence structure was also established. It was founded under Decree № 94 dated 09.09.1915 of Tzar Ferdinand, which constituted "The Regulations on the Safety of National Defense Service".

The National Assembly exercised control over the security structures through enquiries directed to the Minister of Interior and by voting for the budget of the Ministry.

Since 1924, consistent steps had been taken to establish a new legislative framework regulating the activities of the security structures with the purpose of their gradual separation from the Ministry of Interior. The counterintelligence, together with intelligence, was a part of a joint structure called State Security. The first legislative act stipulating its functions was the Protection of the State Act (1924). In the following year, the Administration and Police Act was passed which determined the legal framework of the State Security activities and defined its basic responsibilities. From 1944 to 1946 the State Security was also assigned with investigative functions.

In the 1950s regulative measures were taken in order to reinforce the specialized counterintelligence unit within the State Security by incorporating in its structure the integrated technical departments of the Ministry of National Defense and the Ministry of Interior.  

In the beginning of the 60s, the State Security was a part of the Ministry of Interior and its structure comprised separate directorates and unites.

In 1963, by virtue of a Decree of the Presidium of the National Assembly, a Committee for State Security to the Council of Ministers was established. In the same year Regulations on the structure and the functions of the military counterintelligence were enacted, precisely defining its tasks.

After passing a new Penal Code in 1968, the Presidium of the National Assembly adopted Decree № 1156 on structural changes in the Council of Ministers and in the governmental institutions. The integration of the Ministry of Interior and the Committee for State Security was enacted under the same decree.

In the 1990s a reform of the Bulgarian special services began. The Military Counterintelligence Directorate was separated from the State Security and was placed under the supervision of the Ministry of National Defense. In 1991, a new Ministry of Interior Act was passed, defining a new legislative framework of the national security system.

On the 1st of January 2008, with the enforcement of the State Agency for National Security Act, a new specialized body under the Council of Ministers was established to conduct the national security protection policy. The Agency was constituted in order to meet the public expectations of higher effectiveness in the fight against corruption and organized crime, sharing the experience of its NATO and EU partners in its work.

Four specialized structures were integrated within SANS: the National Security Service, the "Protection of communication means" Directorate, part of the Security Service "MP and MCI" and the Financial Intelligence Agency.

Control over SANS is exerted by a specialized Standing Committee to the National Assembly.

On the 27th of December 2007, the first Chairperson of SANS, Petko Sertov, was appointed.

SANS’s Professional Holiday is on 4th of January – the day of the promulgation of the Capital Municipality Police Act (4th of January, 1907), which is accepted as the birth date of the Bulgarian counterintelligence.

Chairpersons of SANS

Petko Sertov

Petko Sertov graduated from Karl Marx Higher Institute of Economics (HIE), Sofia (today known as University of National and World Economy) in 1982, specializing in Finance, Accounting and Foreign Trade Control.

In 1991-1992, he graduated from the Institute for Senior Police Officers to the French "National Police" - "Ecole Nationale Superieure de la Police (ENSP)" in Lion, France.

Since 1984 to 1997, he worked in the Ministry of Interior. Within the private sector, he worked as an expert and a manager of "Dekom – Analysis and Prognosis Centre".

In 2001, he was appointed Security Expert in the Administration of the Bulgarian President Georgi Parvanov.

In 2005, he was nominated as Secretary of the Security Council to the Council of Ministers.

On the 27th of December 2007, he was appointed Chairperson of the State Agency for National Security. On the 10th of August 2009, he was dismissed.