COVID-19 update: Sumo's Australian based Contact Centre remains open and at your service.

Request a call back

Sorry you have called us outside our business hours. Try us again Mon - Fri between 8:30am - 5:30pm or tell us your availability within these hours and we'll be in touch.

AnyMorning (9AM - 12:30PM)Afternoon (12:30PM - 4:30PM)


Your energy bill jargon explained

Byline author: Graham Cooke

You’re not alone if you struggle to make sense of your energy bill – between megajoules and off-peak metering, confusing terminology can make it difficult to know exactly what you’re being charged for.

To help you reach your own light bulb moment, we’ve broken down some of the basic energy buzzwords below.

NMI number

Every home or business connected to the electricity network has a National Metering Identifier (NMI) number. This is a unique 11-digit number used to identify every single electricity network connection point (or meter) in Australia. At Sumo your NMI number can be found on the second page of your bill in the “Your electricity usage in detail” section.


MIRN stands for Meter Installation Registration Number (also referred to as a Delivery Point Identifier or DPI in some states). This has a similar function to an NMI number, and is used to identify gas network connection points, rather than electrical ones. It is also found on the second page of your bill.

Kilowatt hours (kWh)

A kilowatt hour is a unit of energy that measures how much power a home (or business) has used. One unit is equal to the amount of energy consumed by a 1,000-watt appliance for one hour. For instance, if you turned on a 100-watt light bulb, it would take 10 hours to go through 1kWh of energy.


A joule is a unit of energy. Natural gas customers will have their units of usage measured in megajoules (MJ) through a gas meter. One MJ is equal to 1 million joules.

Peak and off-peak metering

Electricity rates are reduced during specific times when most homes and businesses are using less electricity. This is known as off-peak. While these time frames can vary depending on location, they’re generally at night or on weekends. If you want to take advantage of off-peak metering, you may need to change your tariff (this is the way your energy provider charges you for electricity).

Supply versus street address

A supply address is the location listed for your meter in the National Database. It will often be different to your street address and can sometimes cause confusion among energy customers, who think they’re being billed for the wrong property. You can double-check your supply address is correct by comparing your meter number and supply address located in the same section of your Sumo bill.

Smart meter

Unlike traditional meters, a smart meter will record electricity usage per kWh every half hour. It then sends this information to your electricity provider for billing purposes. Because of this, your energy company doesn’t have to send someone out to read your meter – meaning you won’t receive any estimated bills, and can be sure you’re paying the correct price each month.

If you ever have any questions about your Sumo energy bill, Sumo’s South Melbourne based service team are more than happy to help.

Graham Cooke is energy expert at Finder

Bundle & save on electricity, gas and internet