The erstwhile Andhra Pradesh State Electricity Board which came into existence in 1959 was responsible for Generation,Transmission and Distribution of Electricity.Under Electricity Sector Reforms agenda,Government of Andhra Pradesh promulgated Andhra Pradesh Electricity Reforms Act,1998.The erstwhile APSEB was unbundled into one Generating Company (APGENCO),One Transmission Company(APTRANSCO) and Four Distribution Companies (APDISCOMs) as part of the reform process.
APTRANSCO came into existence on 1.02.1999.From Feb 1999 to June 2005 APTRANSCO remained as Single buyer in the state-Purchasing power from various Generators and selling it to DISCOMs in accordance with the terms and conditions of the individual PPAs at Bulk Supply Tariff(BST) rates.
Subsequently,in accordance with the Third Transfer Scheme notified by GOAP,APTRANSCO ceased to do power trading and has retained powers of controlling system operations of Power Transmission
As per AP Reorganization Act 2014, APTRANSCO was divided into TSTRANSCO and APTRANSCO. Accordingly TSTRANSCO was established as a Company w.e.f 2-6-2014 for the State of Telangana.