Within the responsibilities specified in the Energy Law Act (art. 9c par 2) the transmission system operator:

• contributes to the security of electricity supply by ensuring security of the power system operation and adequate transmission capacity,
  
  
• provides the operation of the transmission system in an effective manner whilst ensuring the required reliability and quality of supply and in cooperation with Distribution System Operators - in the coordinated  part of the 110 kV network,
  
  
• maintains the transmission system, including interconnections with other power systems, in a manner which ensures reliable operation of the power system,
  
  
• ensures the long-term ability of the power system to meet reasonable domestic and cross-border demands for the transmission of electricity, including development of the transmission power system, and, where appropriate, development of interconnections with other power systems,
  
  
• cooperates with other transmission system operators and energy enterprises in order to ensure reliabe and effective operation of the power systems and to coordinate their development,
  
  
• dispatches the generation units connected to the transmission grid and the generation units of the installed capacity equal to or more than 50 MW, connected to the coordinated part of the 110 kV  network with due regard to the contracts with the transmission system users and technical constraints in the system,
  
  
• manages congestion on the interconnections with other systems,
  
  
• purchases the ancillary services and provides system services necessary for the secure, reliable and efficient electricity system functioning,
  
  
• balances the power system, including the service of the imbalance settlement of system users,
  
  
• manages electricity flows in the transmission system and in cooperation with Distribution System Operators - in the coordinated 110 kV network,
  
  
• purchases electricity to cover the transmission losses, with due observation of transparent and non-discriminatory market-based procedures,
  
  
• provides system users and other interconnected transmission system operators with the information necessary for the access to and use of the transmission network, regarding conditions for transmission services, including in relation to the cross-border exchange of electricity, network operation and balancing,
  
  
• prepares the power system defence and restoration plans,
  
  
• exercises power supply restrictions imposed in line with the laws and regulations in force.