What Is an NMI number? How to find yours in Australia

If you've ever tried to switch electricity retailers, request a meter reading, or connect power to a new property, you've probably been asked for your NMI number. 

But what is it? And why is it important?

This guide will answer all your NMI questions, including what an NMI number is, why it exists, and exactly where to find yours.

Quick facts

• NMI stands for National Metering Identifier.
• It's a unique number assigned to your property's electricity connection point, not to you personally or to your retailer account.
• It's 10 or 11 digits long, depending on the network.
• You'll find it on your electricity bill, in the section that lists your supply or account details, not on the meter itself in most cases.
• Your NMI is issued by your local electricity distributor (the "poles and wires" company), not your retailer.
• It normally stays the same when you switch retailers. It only changes if you move house or your connection point is rebuilt.

What does NMI stand for?

NMI stands for National Metering Identifier. It's the identification number used across Australia's electricity network to uniquely identify a specific connection point. In a residential context, this is almost always the electricity meter serving a single property.

What is an NMI number for?

Every property connected to Australia's electricity grid is assigned its own NMI. The NMI is used to identify your supply address, identify the meters and meter types installed at that address, and make sure the right amount of energy is billed to the right account.

In practice, that means your NMI is used to:

• Connect a new electricity account to the correct property.
• Transfer your account when you switch retailers, so the new retailer knows exactly which meter to bill.
• Match meter readings and usage data back to your address.
• Give electricians and installers a reference number when doing wiring or meter work at your property.

The NMI is issued by your local distributor rather than your retailer. This is why the number generally stays the same even if you change who you buy electricity from.

It only changes if your connection point itself changes, for example if you move to a different property or your existing property is demolished and rebuilt.

How to find your NMI number

Almost everyone will find their NMI on their electricity bill, though the precise location may differ depending on your retailer. According to AGL, your NMI appears under "Your electricity supply details" on the top of page 1 of your bill, in the "Your details" section. Red Energy places it in a similarly prominent spot, in the "Your Account Details" box on the first page of the bill.

The exact box label and position vary slightly between retailers, but it's consistently near the top of the first page, next to your address and account number.

It's generally not on your electricity meter

Interestingly, the NMI generally isn't printed on the physical meter itself. Distributor guidance from Ausgrid describes finding the NMI on the bill, not on the meter housing.

What you will usually find on the physical meter is a separate meter serial number, which identifies that specific piece of hardware. It's a different number from your NMI, and it isn't a substitute for it if a form or application specifically asks for your NMI.

If you're trying to read a number off your meter for a self-read submission, that's your meter serial number or your current reading, not your NMI.

If you don't have a copy of your bill

If you can't locate a bill, a few options can help:

• Log in to your retailer's online account portal or app, where the NMI is usually listed alongside your account details.
• Contact your retailer directly and ask them to confirm the NMI for your account, quoting your address.
• For property transactions or new connections, your electrician or the previous occupant's retailer may already have the NMI on file.

NMI format: how many digits, and does it ever change

Your NMI is either 10 or 11 digits, depending on the network area. Ausgrid confirms its own NMIs are 11 digits, falling within a specific numeric range for its network area. The exact numbering ranges differ by distributor and state, which is why two NMIs can look quite different even for properties a few suburbs apart.

Your NMI is tied to the connection point, not to you as a customer. The NMI stays the same unless the location of the electricity network connection point changes, for example if a building is demolished and a new meter installed.

If you move to a different address, you'll be assigned a new NMI for that property. Switching to a high-voltage connection can also trigger a change, though this is uncommon for standard residential properties.

NMI vs MIRN vs DPI: what's the difference?

The NMI only applies to electricity. Gas connections use a different identifier, and the name of that identifier depends on which state you're in.

According to AGL:

• In Victoria, Queensland, South Australia, and Western Australia, the gas equivalent is called the Meter Identification Reference Number, or MIRN.
• In New South Wales, the gas equivalent is called the Delivery Point Identifier, or DPI.

Both are found in the same place as the NMI: near the top of page 1 of your bill, this time your gas bill rather than your electricity bill.

If you're on dual-fuel with the same retailer, your bill will typically list your NMI and your MIRN or DPI separately, since they identify two different connection points.

Who actually uses your NMI number?

You'll be asked for your NMI in a few specific situations:

• Switching retailers. Your new retailer uses your NMI to confirm exactly which connection point they're taking over billing for.
• Moving house. Setting up a new connection or transferring an existing one both rely on the correct NMI for that property.
• Electrical work. Red Energy notes that electricians may need to include your NMI on paperwork for work carried out at your premises, and that a newly built property needs an NMI issued before an electrician can connect it.
• New connections. If you're having a meter installed at a property that's never had one, an NMI has to be assigned before that connection can go live.

You generally don't need to memorise your NMI or carry it around. It's worth knowing where to find it on your bill so you're not caught out the one time you actually need it.