Participant implementation

This section assists market participants in identifying the high-level changes they need to make to implement 5MS and, where relevant, GS. It also leads to the key information needed to make the relevant changes. 

The information provided by AEMO on 5MS and GS is general and may not be appropriate for any participant’s particular situation or market activities. Please also refer to AEMO’s privacy and legal notices.

  • I am a market participant, where do I start?
    1. Familiarise yourself with the 5MS and GS changes and gain an understanding of how AEMO’s 5MS and GS program will coordinate and support the industry through these reforms.
    2. Read the general information below before selecting the type of market participant that you represent. 
    3. Review the specific information relevant to your market participant type.
    4. Where your business has already been engaged in the 5MS/GS program, AEMO encourages you to speak directly with your representatives for background information and the current context. 
  • What does my business need to do? How and by when do we make these changes?

    Every participant is different, and each participant will need to identify and implement the 5MS and GS changes it needs to make and the timeframes in which to make them. 

    By way of guidance, the 5MS and GS Market Readiness Strategy is the overarching plan for AEMO and NEM participants’ readiness activities for these market reforms. It sets out the approach for participants and AEMO to perform:

    • Transition and market system go-live planning and execution
    • Industry testing and market trials
    • Readiness reporting
    • Risk and contingency management
    • Metering service provider accreditation updates for metering providers and metering data providers

    The Market Readiness Strategy is supported by a series of readiness documents, which each cover a specific area of readiness in more detail. For example, the Industry Transition and Go-Live Strategy provides:

    • high-level transition to and market system go-live schedules for 5MS and GS
    • AEMO’s and participants’ 5MS and GS transition responsibilities for 5MS and GS

    The strategy in turn is supported by detailed transition plans, cutover plans and a contingency plan that provide further guidance to participants on implementation. 

    The Readiness Working Group (RWG) is a participant forum that helps to coordinate 5MS and GS readiness activities across the industry. For more information on the RWG or to join, email 

    Each market participant has different requirements to meet its 5MS/GS obligations. For implementation activities relevant to your business, please refer to the implementation information for your NEM participant type or contact us at 

  • Which AEMO procedures have changed?

    AEMO has completed the necessary procedural changes that enable 5MS and GS. To do so, AEMO established the Procedures Working Group (PWG) - a forum to engage with industry stakeholders during the procedure development process. 

    AEMO identified approximately 70 procedures, policies and guides that are affected by the 5MS rule across four functional areas. These procedures were grouped into packages for consultation: metering, settlements, dispatch and power system operations.

    Each market participant will be affected differently by 5MS and GS-related procedure changes. For procedure changes relevant to your business, please refer to the implementation information for your NEM participant type.

  • Which AEMO systems will change?

    Changes to several NEM market systems are being made to support the introduction of 5MS and GS: 

    • The rationale and timing for the market system changes are described in the 5MS/GS Industry transition and go-live strategy. 
    • The high-level approach and timing for testing market system changes (prior to go-live) are set out in the 5MS/GS Industry Testing and Market Trials Strategy.

    The key market system changes are set out in the table. Current information on system release timing is available on the most recent program timeline.



    Impact on participants

    B2M via APIs

    Progressive introduction of API capability for B2M transactions while maintaining current interfacing options. This approach: 

    • Provides participants the option to adopt APIs in-line with their own technology programs 
    • Establishes APIs well before the 5MS-related increase in metering data volumes.

    FTP transactions will remain open for the foreseeable future after 5MS goes live i.e. switching to API is not a mandatory part of the program.

    Will only affect participants who choose to adopt the APIs. 

    Post implementation, participants can deploy their system upgrades at a time of their choosing. 
     Reallocations Introduction of online transaction and API reallocation capability on a 5-minute basis. This provides participants with the capability to enter into 5-minute-based contract reallocations for periods beyond 5MS commencement (1 October 2021). 30-minute reallocations will be supported up to 30 September 2021. 
    Affects all participants who submit reallocations for periods beyond 1 October 2021 via online screens.

    Post implementation participants can deploy API integration upgrades at a time of their choosing. 
    MDM platform delivery

    Introduction of the upgraded MDM platform on a 30-minute settlement “like-for-like” basis, providing:

    • capability option for MDPs to deliver 5-minute metering data as well as 15- and 30-minute metering data for settlement purposes
    • the CATS configuration necessary to support GS standing data updates, providing the option for participants to commence updating NMI Standing Data
    • RM report updates

    a period of operational establishment ahead of 5MS commencement. 

    No expected impacts to participants at implementation.

    Post implementation, provides the capability for participants to provide interval metering data in NEM12 format and at 5-minute granularity (subject to agreement between the Metering Data Provide and AEMO).

    Bidding and dispatch platform delivery

    Introduction of the dispatch platform to provide the capability for 5-minute bidding. From 1 April 2021 to 30 September 2021, participants can choose to either: 

    • continue to submit 30-minute bids 
    • start submitting 5-minute bids ahead of 5MS commencement, enabling familiarisation with and providing assurance over key business processes
    • reporting updates

    From 1 October 2021, 5-minute bidding is mandatory, and any 30-minute bids submitted from this date will be rejected.  

    Participants can choose to submit 5-min bids once the new 5-minute capable Bidding & Dispatch platform is delivered. 
    Participants must submit 5-minute bids from 1 October 2021. 
    Settlement platform delivery

    The Settlements Platform will be introduced at the same time as the Dispatch Platform. This is efficient since there are overlaps between settlements and dispatch in the data model. This joint release approach presents a lower risk than independent releases for settlements and dispatch. The settlement platform on deployment will:

    • Support 30-minute “settlement by difference” prior to 5MS commencement
    • Assure platform operational stability prior to 5MS commencement.
    No expected technical impacts to participants. 
     5MS commencement

    Activation of 5MS-specific capability across AEMO’s three major market platforms (metering, settlements and dispatch) where required. This is the final deployment for 5MS commencement and includes the capabilities to: 

    • produce invoices for that settlement week covering both 30- and 5-minute trading intervals
    • provide UFE reports to each Market Customer from 1 October 2021 in support of GS.
    No direct impact to participants at implementation
    NOTE: Participants will need to ensure any system upgrades required to meet 5MS rule commencement is deployed prior to rule commencement.

    GS commencement Activation of GS specific capability: the shift from settlement-by-difference to global settlement occurs. Retailers will be financially responsible for and therefore invoiced for their allocation of UFE.
    Updating of Local Retailer and required Financially Responsible Market Participants NMI standing data to remove the financial liability of a specific Retailer at the Transmission level. AEMO to support this initial standing data update with consequent data alignments performed by participants.

    The 5MS Program Systems Workstream is responsible for the design, development, testing and implementation of AEMO’s systems to support the changes to 5MS and GS. The workstream will also produce the required technical documentation to facilitate participants’ systems changes.

    The systems technical documentation provides the detail of the changes to AEMO’s market facing systems. These documents will describe AEMO’s IT systems changes and therefore support market participants or their vendors to make the required changes to their own systems.

    To implement 5MS and GS related systems changes, AEMO has:

    • Developed a "High level impact assessment" for systems affected by 5MS and/or GS.  It provided a high-level assessment of the changes required to AEMO's market facing systems to implement 5MS and GS.
    • Developed work packages across four IT functional areas to facilitate systems changes and associated consultation: metering, settlements, dispatch/pricing and operations.
    • Established the Systems Working Group (SWG) to seek input from the industry on the technical system and interface changes. For more information on the SWG or to join, email 

    Each market participant will be affected differently by 5MS and GS related system changes. For system changes relevant to your business, please refer to the implementation information for your NEM participant type.

  • How and when can we test the changes against AEMO's upgraded market systems?

    A key component of market readiness is the industry testing phase – the period where AEMO and NEM participants test their market-interfacing business systems against updated procedures and AEMO’s upgraded market systems.  

    The approach to participant testing for 5MS and GS is set out in the Industry Test and Market Trials Strategy. At a high level, the strategy defines the scope, approach, process, responsibilities and overall schedule of the industry testing phase for the 5MS and GS market transition. It is supported by detailed testing plans for each test phase. The content and level of detail of each plan will be appropriate for the type of participant testing to be conducted.

    Note that participants are responsible for:

    • Testing their systems and processes that interact directly or indirectly with AEMO’s market systems. 
    • Arranging bilateral testing with other participants.

    The Industry Testing Working Group (ITWG) is for AEMO and market participants to engage in detailed 5MS and GS testing matters, including assisting in the development of test plans. For more information on the ITWG or to join, email 

    The 5MS Staging Environment (the Staging Environment) allows participants to test their interactions with market systems that have 5-minute adjusted data. However, is it not a market trial environment and comes with limitations. The Staging Environment provides access to some early versions of 5MS & GS capabilities to assist participants with their readiness planning and development. It has been provided to support participants’ systems development ahead of participant testing.

    Participant testing will take place in the AEMO pre-production environment (pre-PROD). This environment is separate to the 5MS Staging Environment and is used by all AEMO developments for at least 4 weeks prior to their deployment into the AEMO systems. 

    Each market participant has different requirements to meet its 5MS/GS obligations, and therefore different needs for testing. For testing activities relevant to your business, please refer to the implementation information for your NEM participant type.

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