When reading an electricity bill, start by checking that the name and supply address are correct. The account number identifies the customer in the retailer’s system. The NMI (National Meter Identifier) identifies the electricity connection point, whereas the meter number identifies the physical meter. There may be more than one meter number on a bill, if there are separate meters for peak and off-peak supply, for instance. It can be worth checking that the meter number on the bill matches the number on the meter – sometimes, particularly in flats or units, these can get mixed up in the records.
Electricity bills typically include prices, or tariffs, for several different parts of the service. These can be called different things by different retailers.
“Service to Property Charge”, “Daily Supply Charge”
This daily fee is not linked to how much electricity you use, though different retailers do charge different amounts, ranging between about 71-107 c/day.
Usage charges – Peak
This is the amount charged per kilowatt hour of electricity used. Different retailers may charge one price for every kilowatt hour a customer uses, or they may increase or decrease the price as the customer uses more electricity in a billing period. On the bill, these tariffs might have a name such as “All Day Rate”, “Anytime Rate” or “Peak Rate”.
Usage Charges – Off-peak
A few appliances are allowed to use electricity at a special, cheaper tariff. These appliances are typically controlled by a timer, and retailers use the terms “Controlled Load”, “Dedicated Circuit” or “Ancillary Load” on bills to describe this tariff. Historically, this was called a “J-Tariff” and is commonly referred to as off-peak. These appliances include storage water heaters (of 125 litres or larger), heaters for pools and spas, underfloor heating, heat bank storage heaters, electric vehicles and household batteries.
Time of Use tariffs
This tariff is recently available to residential electricity connections that have a Smart Meter that can transmit a reading every half hour. Rates change depending on time of use. The peak period (the most expensive) is from 6am to 10am and from 3pm to 1am. A second tariff is available from 1am to 6am and the cheapest (‘shoulder’) is from 10am to 3pm.
Electricity retailers usually include an explanation of how to read their bill on their website – if you’re having trouble making sense of a particular retailer’s bill, that page of their website may be helpful.