Understanding your electricity bill

The first thing people look at when opening an electricity bill is the amount owing, but there is much more information in your bill such as:

  • meter numbers
  • average daily usage
  • whether your last meter read was estimated.

Our guide helps you to find what you are looking for and provides an explanation of what each component means.

If you have any concerns over something on your bill, or if you need further help understanding it, you should first contact your electricity supplier.

What is your bill telling you?

Many people have trouble understanding their electricity bills, or knowing where to find specific information.

Some of the things you will find on your bill are:

  • your supply address
  • payments you have made since your previous bill
  • any amounts still outstanding, as well as new charges for the current period
  • the billing period for the current bill
  • your average daily usage in units and dollars
  • your meter number(s) (National Metering Identifier or NMI)
  • the previous and current readings taken from the meter(s)
  • an approximate next scheduled meter read date.
Have you asked your supplier?

Many suppliers have a section on their website where they explain their bills. They are also able to explain the details over the phone. To find our your supplier's contact details, please click here.

What should you check for on each bill?
  • Your account or customer number
  • Whether the meter readings are actual or estimated.
  • If you receive concessions, check that they have been applied. Contact your electricity retailer or refer to Department of Human Services for more information.
  • If there are any amounts outstanding from previous bills.
  • If there are any messages from your supplier relating to changes to your bill (i.e. rate increases, notice of no access leading to estimated usage).
  • If you have solar panels installed, check that your supplier has applied solar feed-in tariff.
Breakdown of your bill

You will usually find the following on the front page of your bill:

  • Issue date: The date that the bill was generated by the retailer.
  • Account number and/or customer number: This is your account number. You should quote this any time you call your electricity retailer.
  • Your name and postal address: The postal address may differ from the supply/service address (i.e. Post office box).
  • Due date: The last day by which you must pay your bill.
  • Billing period: The range of dates the bill covers (e.g. 1 January 2015 – 1 March 2015) and bill days.
  • Opening balance: The amount that was owed, or in credit, when the previous bill was issued.
  • Payments received: The amount you have paid since the previous bill.
  • Balance carried forward: The difference between the opening balance and the payments received. If you did not pay your last bill in full by the due date, a balance may be carried forward and added to your new charges. It is possible that you may have a credit carried forward.
  • New charges/current charges: The new charges for the billing period covered by this bill.
  • Discounts or credits: Any discounts that are applied to your account in accordance with your plan, such as pay-on-time discounts or solar credits.
  • Total amount due: The total amount that you currently owe. This may be split into two amounts if your plan has a pay-on-time discount (with and without discounts if paid by due date).

The following items are commonly found on the second or third page of your bill, although some elements may appear on the first page.

  • Service address/supply address: The address the retailer is billing you for (may vary from the postal address).
  • Next scheduled read: The date that your meter will next be read (may be two days either side of this date).
  • Last meter read: The last date that your meter was read (this will be the end date of the billing period).
  • NMI (National Meter Identifier): The unique numerical identifier used by the industry to identify the supply point/(s) at your property.
  • Tariff: Will be your plan name.
  • Meter number: The numerical equipment number on your meter.
  • Bill days: The number of days in the billing period.
  • Previous read: The read taken from your meter at the end of the last period/start of this period.
  • Current read: The read taken from your meter at the end of the billing period (which will become the previous read on your next bill).
  • Actual (A)/ Estimated (E)/ Substituted (S) / Final Substitution (F): Indicates the type of meter read carried out and is located near the previous and current meter reads.
  • Total kWh usage: Your total consumption, in kilowatt-hours, for the billing period.
  • Unit price/rate: The amount you are charged per kilowatt-hour.
  • Supply charge/service charge: A charge applied for the supply of electricity to the property. It covers the costs involved in the transmission and distribution of electricity, including maintenance of the network infrastructure.
  • Solar generation (may be called PV generation, export, Feed-in): If you have a solar system installed on your property, the number of solar generated units of electricity exported to the grid, and the dollar value of these units is indicated here.
  • SA Government concession: The amount of any government concessions applied.
  • Average daily usage: The total number of kilowatt-hours consumed in the billing period divided by the number of days of the billing period.
  • Same time last year: Your average daily usage from the same period last year.
  • Average daily cost: The dollar value of your average daily consumption.
  • Total greenhouse gas emissions: Total amount of greenhouse gas emissions for the billing period of this bill.
Are you concerned about your bill?

If you feel that there is an issue with your current bill, you should first take the time to thoroughly read it, compare it to previous bills (especially the bill from the same time last year), and write down the issues that you wish to raise with your retailer, including why you believe there is an issue (and any supporting information) and what you are seeking as a resolution.

If you have a clear understanding of the bill and the issue, you will be better equipped to ask the right questions when you speak with your retailer.

Understanding a high electricity bill

Many factors can contribute to a high electricity bill. It is not necessarily a mistake. Understanding why your bill is high is a process of elimination. Is it because you have used more electricity? Is it because your rates have changed and you are now paying more for what you do use?

It is important to understand your bill before contacting your electricity supplier.

Taking time to read the bill properly and comparing it to previous bills (including the amount used and the rates charged) will help you understand why the bill is higher and then you will be able to address the issue more effectively.

Let us guide you through some of the most common causes of high bills.

Has your usage been estimated?

Check your current and previous bills for the word ‘estimated’ (or the letter ‘e’) or 'substituted' (or the letter 's') next to the meter read. Your meter read may have been estimated rather than actually read.

When a bill is estimated, it can often result in your estimated usage being lower or higher than your actual usage. If your circumstances have changed in the last year your usage may be different. For example, you may have acquired new appliances or had additional people staying.

Your next bill, based on an actual read, will bring your account back in line with the current reading on your meter. If your previous estimated bill was too low, your next bill may be higher than you expected. Similarly, if your bills have been overestimated, you will eventually receive a reduced bill.

No matter how many estimated bills you have received in a row, once an actual read has been obtained, you will be billed for - and pay for - only the electricity you have actually used.

Your meter should ideally be read at least every three months and the supplier must use their best endeavours to obtain an actual meter read at least once every 12 months.

Equally, you have an obligation under law to provide safe and unhindered access to your meter location at all times.

Have you used more electricity?

Every electricity bill contains valuable information about your usage.

Next to the graph on the bill, you will see your ‘average daily use’ for the current bill as well as for the same time last year.

‘Average daily use’ is calculated by taking the total kilowatt-hours (kWh) of electricity used in the billing period and dividing the number by the number of days in that period. How does your current average daily use compare with that of the previous year? Is it a higher number? Does it indicate you have used more electricity than last year?

To understand why you may have used more electricity, look at the billing dates on the bill and think about what happened during that period.

  • Did somebody in your household spend more time than usual at home, or did you have guests staying?
  • Did you use a heater or air conditioner more during a hot/cold period?
  • Did you buy or use any additional appliances?
  • Did you do any renovations or landscaping, using electrical equipment?
  • Is the billing period itself actually longer?

If you have a basic meter which allows self reading , you can do your own estimation of how much electricity you use on a regular day.

To do this:

  • Take a meter read at a set time on a typical day.
  • Take another read the next day at the same time.
  • The difference between the two meter reads is the amount of electricity you used in the last 24 hours, which is an indication of ‘average daily usage’.
  • If you have a remotely read interval meter or smart meter, you may be able to access your meter reading using a mobile device app or an online portal. Please speak to your supplier if you need help in accessing this information.

When you compare your meter read with the ‘average daily usage’ on the high bill and find that you are using a high volume of electricity, you may need to seek advice on how to manage your usage and reduce future bills.

Remember, a small amount of additional usage each day can equals a significant increase in your bill.

Consider the following scenario:

  • Your usage for the same quarter last year was 5 kWh per day.
  • This year your usage has increased slightly to 8 kWh per day.
  • So on average you have used 3 kWh extra per day across a 90-day bill.
  • 3 kilowatt-hours x 90 days = 270 kWh of additional usage in the quarter compared to last year.
  • If you were paying 30c per kWh for your usage that would equal an additional $81.00 on your bill.
Have your electricity rates increased?

Your electricity contract will outline how your retailer is required to advise you of increases to your electricity rates.

They may notify you in writing, by a letter with the bill or by a notice on the bill itself.

Compare the rates on your high bill to the rates your previous bill, or to the bill from the same time last year. Are you paying more per kilowatt-hour?

You may see ‘summer rates’ listed on your bill. Some energy plans or contracts charge higher rates during the summer months from January – March.

Keep in mind that a high bill may be a combination of an increase in your electricity usage and an increase in what you pay for usage.

If you have any questions about your rates, you should contact your electricity retailer.

Is there a 'balance brought forward'?

Did you pay all outstanding amounts before your current bill was issued? If not, then your bill is likely to include any previously unpaid amounts as well.

Your bill will show you two figures:

‘Balance brought forward’ – any balance (still owed or in credit) at the time the new bill was issued

‘New charges’ – the charges for the current billing period

You may think you have received a high bill when, in fact, your new charges are in line with your previous bills. If charges from a previous period remain unpaid, they will be added to the new charges for the current period and the total owing will be a higher figure and appear to be a ‘high bill’.

If you need assistance with payment options you should contact your electricity retailer.

Have you checked the meter details?

Check that the meter number on the bill matches the meter number(s) at your property.

If they do not match you should immediately contact your retailer.

Additional charges or missing concessions?

Are there any establishment fees, administration fees, connection or disconnection fees, late fees, early termination or exit fees?

Are any expected concessions missing?

If so, you should contact your electricity retailer or refer to Department of Human Services for more information.

Understanding your electricity meter

Learning how to read your meter can be a handy skill to have and it is not difficult to learn.

Being able to read your meter will allow you to monitor your daily usage, to check the use of individual appliances, to check for possible electrical faults and to take action promptly instead of finding out from your next bill that something may be wrong.

The information below provides details about your meter, about the rights and responsibilities regarding reading your meter and provision of access.

Meter identifiers

Each electricity meter has a unique serial number on the front.

You should quote your meter number when you contact your supplier, especially if you are moving house and arranging a final read, transferring to a new provider, or if your address is difficult to locate.

As each meter has its own number, your meter number changes when your meter is replaced.

Your property may have more than one meter. You can find the meter number on the meter and on your electricity bill.

There is also a second identifier called a National Metering Identifier (NMI). The NMI is a unique identification number attached to your address and not your meter.

Some properties may have more than one NMI, and an NMI can have more than one meter attached to it. You can find your NMI on your electricity bill.

Where is your meter?

Meters are usually in obvious places at the front or back of a property.

If you are in a unit complex, it is likely that all the meters are in a central location.

Some older units may have a meter inside the unit, or there may be one central meter where the consumption is recorded and the landlord determines how it is apportioned.

Who reads your meter?

Usually the distributor (the entity that owns the poles, wires, pipes and meters) reads your meter, and will provide the meter readings to your retailer for billing. However, some newer meters are ‘smart’ meters that can be read remotely by the retailer.

It is your supplier’s responsibility to ensure a reading is taken as frequently as required, which is at least once every 12 months, and to advise you if they have not done so.

The date of your next meter read is shown on your energy or water bill. It is an approximate date only.

Suppliers and their representatives, such as meter readers, must carry official identification and show it if you ask to see it when accessing your property.

Access to your meter

You must provide safe and clear access to your meter for maintenance, meter readings and connecting or disconnecting supply. If you live within a secure complex, your distributor will have access arrangements with the complex manager.

If the meter reader can’t get access to your meter, the supplier will estimate your meter read for billing purposes. Your bill will show it is estimated. If access to the meter continues to be denied, your retailer has the right to disconnect or restrict supply.

If you cannot provide clear access, contact your supplier to find out what other arrangements you can make. Smart meters are gradually replacing the traditional physical reading of electricity meters. Smart meters can be read remotely so meter readers will no longer be required to attend properties for every reading.

Are you being billed for your meter?

The meter number on your bill should match the number on the meter at your property.

If you have peak and off-peak meters, make sure that they match with the meter numbers on your bill.

If they do not match, or any are missing, you should contact your retailer, provide the correct meter number(s) and ask them to amend your bills.

If your meter is grouped with many other meters, you may want to check which meter is yours. You can do this by turning off the main switch to your property for a few minutes and see if the meter you believe to be yours stops recording usage (the dial stops spinning and/or the numbers stop progressing).

If the meter does not stop, it could mean:

  • it is not your meter. Check to see if one of the other meters has stopped - that may be your meter.
  • there may be something else connected to your meter that you are not aware of (a shed, or something from a neighbouring property or common areas).
  • the meter may be faulty. You can contact your retailer and arrange a meter test. Be aware that the test is at your cost unless the meter is found to be faulty. It is not common for meters to be faulty, so a meter test should be the last resort.

Also, take note of any lights or other electrical appliances around your property that stop working when you turn off your main switch. Look at neighbouring properties or community lighting. If they stop working when you turn off your main switch it may mean that your meter is supplying their power as well and you may be charged for that power also.

How to read your meter

If you know how to read your meter, you can keep track of your usage between bills and check that your bills are correct when you receive them.

There are different types of electricity meters.

Dial Meters have small clock faces and are read left to right, ignoring the dial marked 1/10, and you record the numbers from each dial.

  • If the pointer is between two numbers, record the lowest number.
  • If the pointer is directly over a number, draw a line under it when you write it down.
  • Of the underlined numbers, if any are followed by an 8 or 9, then reduce the number by 1.

Digital meters are meters with digital displays, and are again read from left to right, ignoring numbers after the decimal point.

A digital meter has the ability to record different types of use.

  • Register 3 will show peak use.
  • Register 7 will show off-peak use.
  • Register 9 will show solar (PV) generation, if applicable.

Calculating your usage

Your electricity meter records your usage in kilowatt-hours.

By taking the current read and subtracting the previous read, you can calculate your usage by dividing by the days between the reads to give you a daily average.

This is how the average daily usage listed on your bill is calculated.

If you have any doubt or are not sure about the reading, you should contact your retailer.

How to check your electricity usage

Understanding how to use your meter to monitor your household electricity use can be extremely beneficial, especially if you receive a bill that is higher than expected, or if you think you may have a faulty appliance or meter.

You can also measure the consumption of specific appliances and calculate how much the appliance costs to run, or identify if it is using more power than it should. This will help you to control your usage so you will not be shocked by your next bill.

How to measure your electrical usage

You can perform a simple test to determine how much power you use at your property.

The number of kilowatt-hours of electricity used per day to run your house before any additional appliances are used is often referred to as the base electricity consumption.

To measure your base electricity consumption:

  • Turn off all electrical appliances except for anything essential.
  • Take a meter read and note the time that the read was taken.
  • Do not use anything but essential appliances in the next 24 hours.
  • Take a meter read at the same time the next day.
  • Subtract the previous read from the current read and you are left with the number of kWhs you use as a base on any given day.

To measure your electricity use on an average day:

  • Take a meter read and note the time that the read was taken.
  • Use your electrical appliances as you normally would on an average day.
  • Take a meter read at the same time the next day.
  • Subtract the previous read from the current read and you are left with the number of kWhs used per day on an average day.

The test allows you to see the difference between your electricity usage on an average day and your base electricity consumption. If there is a big difference, you may want to reduce your use of non-essential additional electrical appliances.

We recommend regularly measuring your daily consumption to monitor whether you have successfully reduced your consumption after a high bill.

How to measure the usage of an appliance

Locate the input power of the appliance. It is often listed on the appliance itself or on its tags or manuals.

  • If the listing is in watts – divide the watts by 1000 to give you the kilowatts.
  • If the listing is in amps and volts – multiply the amps by the volts to get the watts, and then divide the watts by 1000 to get the kilowatts.

Mechanical Electricity Meters

  1. Turn off all appliances, lights, etc.
  2. Turn on the appliance being measured.
  3. On the rotating disc, there is a black mark to assist with counting the revolutions.
  4. Count the number of revolutions the disc makes in one minute while the appliance is running.
  5. Multiply that number by 60 (to calculate revolutions per hour).
  6. On the information plate there is a number labelled as “RPK” or “Revs per kWh”. Divide the number of revolutions per hour by the RPK.

The result is the kilowatt rating of the appliance.

For example, when you count 10 revolutions per minute and the RPK is 400, you would calculate the rating as follows:

  • 10 x 60 = 600 revolutions.
  • 600 ÷ 400 = 1.5 kilowatts.

The appliance is therefore rated at 1.5 kW, and if used for one hour, the appliance would use 1.5 kilowatt-hours (kWh).

Electronic Electricity Meters

  1. Turn off all appliances, lights, etc.
  2. Turn on the appliance being measured.
  3. On the face of the meter, there will be a pulsating signal - either a small light or an indicator on the display screen. Each pulse registers one watt-hour.
  4. Count the number of pulses in one minute while the appliance is running.
  5. Multiply the number by 60 (to calculate pulses for every hour).
  6. Divide the number by 1000 (to convert the watts to kilowatts).

The result is the kilowatt rating of the appliance.

For example, where you count 25 pulses per minute you would calculate the rating as follows:

  • 25 x 60 = 1500 watt-hours.
  • 1500 ÷ 1000 = 1.5 kilowatts.

The appliance is therefore rated at 1.5 kW and if used for one hour, the appliance would use 1.5 kilowatt-hours (kWh).

What is the cost to run an appliance?

Check your electricity bill to see how much you pay per unit for your electricity (if you do not have your bill, 32c per kWh is an average price) and take your previous calculation of kilowatt-hours.

Multiply the kilowatt-hours by the unit price and you will have the running cost per hour for your appliance.

1.5 kWh x 32c = 48c per hour

If you run the appliance for 5 hours a day, it would cost approximately $2.40 per day to run.

48c x 5 hours = $2.40 per day

If you run the appliance for 5 hours every day for the duration of your billing period, then that one appliance alone would cost you approximately $216 for a quarter.

$2.40 x 90 days = $216

You can see how quickly the costs of using certain appliances can add up.

If the appliance was a heater being used during a cold period, even using it every second day for 5 hours (or every day for 2.5 hours) would still add approximately $108 to your bill.

We recommend you compare your bill to the same period last year for a realistic comparison.

For further information regarding appliance energy use, please refer to the Energy Advisory Service.