Market liquidity obligation

The Market Liquidity Obligation (MLO) is a market making requirement designed to facilitate transparency and liquidity in the trading of electricity futures contracts relating to a forecast reliability gap. 

The MLO commences when the Retailer Reliability Obligation (RRO) is triggered and provides a source of qualifying contracts for liable entities to purchase to help meet their RRO contracting requirements.

MLO determinations and variations are made by the AER in accordance with the Interim MLO Guidelines.

Go to the Interim MLO Guidelines

The AER facilitates an online RRO Generator Portal to streamline the provision of generator information. 

If you believe you should have access to the portal, please contact the RRO team. The AER has also published a guide to assist market participants in using the online portal. Any questions about submitting information through the portal can be directed to the RRO team at RROaer [dot] gov [dot] au (RRO[at]aer[dot]gov[dot]au).

Go to our RRO Generator Portal user guide

The National Electricity Rules require the AER to establish, maintain and publish the MLO register in accordance with the MLO Guidelines. 

Market participants that have scheduled generating units or scheduled bidirectional units in their portfolios are reminded of the requirement to update the information in the RRO portal within 10 business days in the event the details of their scheduled generating or bidirectional units change. This is to ensure the MLO register remains accurate. 

This is necessary for all participants with scheduled generating units or scheduled bidirectional units, not only those existing MLO generators and MLO groups.

If you have any questions about the MLO register, please contact the RRO team at RROaer [dot] gov [dot] au (RRO[at]aer[dot]gov[dot]au).

Latest updates to the MLO register

The MLO register was updated in August 2026. The following changes have occurred:

• reliability gap for New South Wales December 2027 – February 2028 has been forecast not to occur
• reliability gap for Victoria December 2027 – March 2028 has been forecast not to occur
• reliability gap for South Australia January 2028 – March 2028 has been forecast not to occur.

Go to the MLO Register - August 2026

Australian Securities Exchange Limited (ASX 24) and TOD Markets Pty Limited (TOD Markets) are the approved exchanges on which MLO groups, MLO generators and liable entities may trade MLO products. ASX 24 was deemed approved on 1 July 2019, when the Retailer Reliability Obligation commenced. TOD Markets was subsequently approved on 4 September 2026. The two platforms consist of the MLO register of approved exchanges.

The AER’s process for reviewing approved MLO exchanges is set out in the Interim MLO Guidelines and clause 4A.G.23(f) of the National Electricity Rules (the Rules).

The MLO register of products approved for trading on each exchange for the Queensland, New South Wales, Victoria and South Australia regions are listed below.