On 25 January 2000, the ACCC released a revenue cap decision for TransGrid, the main provider of transmission services in NSW and the ACT. The decision also covered the transmission services provided by EnergyAustralia in NSW. In accordance with NSW's transitional rules, the decision was effective from 1 February 2000, even though it applied to the regulatory period commencing on 1 July 1999.

The ACCC's decision draws on consultancy reports, submissions from interested parties and the analysis of data and information presented to the Commission in the course of its deliberations. The decision considers regulatory issues such as the opening asset base, the weighted average cost of capital and the treatment of capital and operating expenditure.

On 6 November 2002, as a result of the Snowy Mountains Hydro Electric Scheme transmission network assets being handed over to TransGrid, the ACCC revoked and substituted TransGrid's revenue cap.