Electricity Transmission Ring-fencing Guideline Review

Ring fencing guideline
Date initiated: 
2 April 2019
Effective date: 
1 July 2021
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 Electricity Transmission Ring-fencing Guideline.

Due to the COVID-19 pandemic, this project was delayed. In August 2020 we released an updated timeline for the review.

Invitation for submissions

We invited interested parties to make submissions on our discussion paper by 31 January 2020. We received nine submissions in total.


The purpose of ring-fencing is to prevent regulated businesses from discriminating in favour of their related parties to the disadvantage competitors operating in these markets. Ring-fencing helps consumers by supporting competition in markets for electricity services and the efficiency of regulated network services.