Central Transmission Utility of lndia Ltd (CTUIL), 100% subsidiary of Power Grid Corporation of India Limited, is notified as the Central Transmission Utility under Section 38 of the Electricity Act 2003. Its functions as per Electricity Act, 2003 are as below:

a. to undertake transmission of electricity through inter-State transmission system;

b. to discharge all functions of planning and co-ordination relating to inter-state transmission system with - (i) State Transmission Utilities; (ii) Central Government; (iii) State Governments; (iv) generating companies; (v) Regional Power Committees; (vi) Authority; (vii) licensees; (viii) any other person notified by the Central Government in this behalf;

c. to ensure development of an efficient, co-ordinated and economical system of inter-State transmission lines for smooth flow of electricity from generating stations to the load centres;

d. to provide non-discriminatory open access to its transmission system for use by-
i. any licensee or generating company on payment of the transmission charges; or
ii. any consumer as and when such open access is provided by the State Commission under sub-section (2) of section 42, on payment of the transmission charges and a surcharge thereon, as may be specified by the Central Commission:

Other functions undertaken by CTU include 

a. Planning Cross-border transmission system
b. Commercial functions associated with billing, collection and disbursement of ISTS charges
c. Planning & coordination for development of secure and reliable national communication system for ISTS & cross border links and nodal agency for its supervision.
d. Own & install interface energy meters for ISTS points.
e. Engineering functions associated with substation and line design alongwith associated secure communication and technical specifications