The Supreme Court of Cassation is the cassation instance for the judicial acts as provided for by law and hears cases as envisaged by law. When a matter of constitutionality is raised for consideration, the Supreme Court of Cassation may refer the matter to the Constitutional Court.

Constitution of the Republic of Bulgaria
Promulgated, State Gazette No. 56/13.07.1991 (effective 13.07.1991), last amended SG No. 12/6.02.2007

Article 124. The Supreme Court of Cassation shall exercise supreme judicial supervision as to the accurate and equal application of the laws by all courts.

Article 150. (1) The Constitutional Court shall act on the initiative of at least one-fifth of the National Representatives, the President, the Council of Ministers, the Supreme Court of Cassation, the Supreme Administrative Court, and the Prosecutor General. Competence disputes referred to in Item 3 of Paragraph (1) of the foregoing Article may furthermore be brought by the municipal councils.
(2) Should it establish an inconsistency between a law and the Constitution, the Supreme Court of Cassation or the Supreme Administrative Court shall suspend proceedings in the case and shall refer the matter to the Constitutional Court.

Judiciary System Act
Promulgated, SG No. 64/7.08.2007, last amendments effective as of 26.03.2013

Article 108
(1) The Supreme Court of Cassation shall be the supreme judicial instance in criminal and civil cases. Its jurisdiction shall cover the entire territory of the Republic of Bulgaria.
(2) The Supreme Court of Cassation shall be seated in Sofia.

Article 109 (2) There shall be a criminal, civil and a commercial college at the Supreme Court of Cassation.