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Back to Basics Series – National Metering Identifiers (NMIs)

We’re embarking on a series of posts that go back to basics. As electricity market experts, too often we come across people and / or businesses who lack an understanding of what can and can’t be done in the market. Inevitably we find that it is difficult to educate if the basics aren’t fully understood. 

There is no doubt that energy markets are highly complex. For example, understanding every aspect of the National Electricity Market (NEM) is near impossible. But a solid understanding of the fundamentals is essential if you stand any chance of knowing some of the more complex aspects of it.

National Metering Identifiers

A National Metering Identifier (NMI) is a unique 10 or 11 digit number used to identify every electricity network connection point in Australia. This includes all types of metered and unmetered electricity connections to the physical electricity networks in the National Electricity Market (NEM), Western Australia markets (SWIS and NWIS) and the Northern Territory.

Learning about NMIs and their function is essential. NMIs allow all the relevant players in the market to identify your network connection point and the associated services, costs and service providers associated with it. NMIs and all the data and information associated with them, are recorded in the Australian Energy Market Operator’s (AEMO’s) Market Settlement and Transfer Solutions system (MSATS), which all key service providers have access to. Put simply, MSATS is the IT system operated by AEMO to fulfil its obligations under the National Electricity Rules (NER). We’ll post on this soon.

Via MSATS, retailers become financially responsible for your NMI in the market, and therefore the costs associated with it. The energy and market costs to AEMO, the network use of system (NUOS) costs to your Network Service Provider (NSP), and the metering costs to your metering co-ordinator (MC). Your retailer is responsible for paying these costs to the relevant providers, and then recovers these costs through charges to you in your retail energy invoice.

Meter data is collected and recorded against a NMI. Any connection related works at your premises must be done with reference to a NMI (for example the installation of embedded generation). NMIs are transferred from service provider to service provider as the preferred party for these services changes, such as retailers and metering providers.

You can find your NMI on your electricity invoice. Noting a NMI will only change if there is a change to the physical connection infrastructure (for example, a change to the connection configuration or voltage) or the physical connection is removed and then later re-established.

In terms of industry speak, NMIs are often pronounced “Nim-ees” or “N M I’s”.

In the coming posts we will focus on the installation of generation at a NMI, including small scale solar PV and larger utility scale installations. How the configuration of generation can influence your consumption requirements from the market / grid and associated regulatory impacts.

Any questions, please don’t hesitate to contact us on 1800 334 336 or email or