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Last updated: 09 Mar 2023

Electricity, gas and water meters

Explaining different meter types and how technology is changing.

Each meter will have a unique meter identifier* – this a number that appears on your bills and is used to identify your specific meter:

  • Electricity meters: National Metering Identifier (NMI)
  • Gas meters: Metering Installation Registration Number (MIRN)
  • Water meters: unique serial numbers.

*If you are an energy customer in an embedded network, you may need to apply for a national meter identifier.

Do mistakes happen with NMIs and MIRNs?

Yes – particularly in transfers from one energy retailer to another. Contact your retailer if you think a mistake has been made.

Can meters measure incorrectly?

There are Australian Standards for meter accuracy. New meters are tested against these standards before installation.

Analogue meter:

These have been phased out and are the ‘old style’ of meters – with a spinning disk and row of figures that keeps adding up your usage.

The meter reading data can be compared to what the meter is showing. If you have peak and off-peak electricity with this old style of meter, you’ll usually have two meters and a time switch.

Smart meter:

A Smart Meter is an advanced interval meter. The record of your electricity use is cumulative (i.e. the number displayed on the meter screen will continue to increase as you use electricity). The meter will also log your usage data internally every 30 minutes. Most households and small businesses in Victoria now have a Smart Meter.

How do Smart Meters work?

Smart Meters record a property’s electricity usage every 30 minutes. Periodically, the reading is transmitted remotely to your electricity distributor (companies that own the electricity poles and wires, and meters themselves), which sends your usage data to your electricity retailer so they can bill you.

This means that meter readers do not have to regularly attend properties to take readings.

Smart Meters also provide detailed, real-time information about power outages and faults to the distributor.

How to read Smart Meters:

Smart Meters record different information in categories otherwise known as ‘registers’, such as:

  • Time and date
  • Total usage
  • Total off-peak usage (if applicable)
  • Solar power exported to the grid (if applicable)
electricity gas water meters - smart meter

You can read these registers on the digital display panel (1).

The Smart Meter will scroll through the registers automatically, but you can press a scroll button (2) to obtain the register you want to read more quickly.

How do I check usage on my bill?

If your bill does not have cumulative readings on it, you can take a reading of the total electricity usage on the day that the meter is scheduled to be read (the date(s) shown on your bill).

If you have the usage figure from the previous scheduled meter read you can subtract that from the new figure to work out your current usage. This figure should approximately correspond with the usage figure on your bill.

Distributor online customer portals

If you’re unable to make the check yourself, your distributor has an online customer portal that lets you monitor your electricity usage.

You will need your National Metering Identifier (NMI) and the serial number of your electricity meter to create an account. This information can be found on your electricity bill.

Unsure who your distributor is? You can search for them on the Victorian Government Energy website:

Can I replace the Smart Meter?

Under the Electricity Distribution Code ( you must not interfere, or allow interference, with any of the distributor’s equipment – including the Smart Meter.

Smart Meters and your health

EWOV is not the appropriate body to investigate the effects of radio frequencies or electromagnetic fields from wireless technologies.

The Australian Radiation Protection and Nuclear Safety Agency sets the human exposure limits for radio frequency electromagnetic energy. The Australian Communication and Media Authority then apply these limits to consumer devices and telecommunications facilities.

If you are concerned about your health and smart meters, visit the Australian Radiation Protection and Nuclear Safety Agency website:

Need more information about Smart Meters?

Visit the Victorian Government’s website at:

Imperial meter: This records gas usage in cubic feet, and can be recognised by a series of ‘clock dials’ on the front of the meter. This style of meter is being phased out.

Metric meter: This records gas usage in cubic meters (M3), and will display a line of numbers that should be read from left to right. Read the black/white digits and ignore those in red.

(Digital versions of metric meters are also available).

Your water company is responsible for your water meter. Most water meters will show a line of numbers that should be read from left to right. Some water companies may use a Smart Meter.

How to read your water meter

high water bills meters
  • The black numbers on the white background measure kilolitres.
  • The white numbers on the red background measure litres.
  • Starting from left to right, the digits measure hundreds of litres and tens of litres, up to litres and tenths of a litre.

Please note: some meters only measure to tens of litres.

High water bills water meter dial
  • The number at the top of the meter measures in kilolitres.
  • The dials from right to left measure hundreds of litres, tens of litres, litres and tenths of a litre.
  • If a hand is between two numbers, note the lower number, except between 0 and 9, then note 9.

Different problems can happen with meters, for example:

  • When you change from one energy retailer to another, the wrong meter may be transferred accidentally.
  • You may experience a customer service issue during the meter installation process.
  • Your meter may be recording your usage incorrectly.
  • Your bill might be based on an estimate.

Some bills are estimated. If the meter reader can’t access your meter (for example, because of locked gates, vegetation or dogs) energy retailers and water companies are allowed to estimate your bill. See our ‘Estimated Bills’ fact sheet ( for more information.

If you receive an estimated bill (and do not have a smart meter), you have the option to provide your own meter reading to your energy retailer by taking a photograph and sending it.

If you have a problem relating to a meter or billing issue that can’t be resolved with your energy retailer, EWOV may be able to help!