KOSTT J.S.C is electricity Transmission, System and Market Operator of the Republic of Kosovo, a public company with 100% of shares owned by the Republic of Kosovo. According to Law on Electricity no. 05/L-085 approved in 2016, the rights of the shareholder will be exercised by the Assembly of the Republic of Kosovo.

KOSTT J.S.C. operates under two licenses issued by the Energy Regulatory Office (ERO).
According to the licenses for Transmission System Operator and Electricity Market Operator, KOSTT is responsible for:

Planning, operation, maintenance and development of Kosovo’s electricity transmission system; Efficient, economic and coordinated operation of the transmission system, including cross-border flows; Balancing of the system; Provision of non-discriminatory access for transmission system users; Encouraging efficient competition in electricity generation and supply; Encouraging economic efficiency in applying Market Rules and performance of activities in compliance with the Market Rules; Administration of a centralized electricity market in Kosovo; Management of the final settlement processes.

KOSTT manages the Transmission System of the Republic of Kosovo, operating with high-voltage 400kV, 220kV and 110kV lines. The transformers connected to the distribution network: 220/35//10 kV and 110/35/10 (20) kV also belong to the transmission system. The responsibility of KOSTT is to transmit electricity safely and reliably from generating units to the distribution system, 24 hours a day, 365 days a year.

Currently, the Kosovo's transmission network is connected to neighbouring countries through seven cross-border lines. In December 2015, the construction of the eighth cross-border line, which is expected to become operational, has been completed

As a result of the central geographical position of Kosovo, the Transmission System operated by KOSTT, although small in size, represents a very important transmission hub in Southeast Europe.