Ring-fencing guideline (electricity transmission) full review

Ring fencing guideline
Date initiated: 
2 April 2019
General enquiries - Ring-fencing AERringfencing@aer.gov.au


On 15 November 2019 the AER released a discussion paper to commence a review of ring-fencing arrangements for transmission network service providers (TNSPs). This paper requested input from stakeholders to inform the development of an updated Ring-fencing guideline (electricity transmission).

Due to the COVID-19 pandemic this project was paused.

In April 2022 we provided an updated timeline for the full review of the Guideline. 

On 31 May the AER released an issues paper. Submissions to the issues paper closed on 22 July 2022.

On 4 November the AER released a draft Guideline and explanatory statement. Submissions closed  on 16 December 2022. 


The purpose of ring-fencing is to prevent regulated businesses from:

  • discriminating in favour of their related parties to disadvantage competitors operating in these markets
  • using revenue earned from regulated services to cross-subsidise unregulated or contestable services.