How to Interpret Your Electricity Bill

Your NMI, tariffs, meter registers and Solar FiT credits — decoded for Australian homeowners

Last Updated: 2026-08-10

Key Takeaways

• Your Electricity Retailer issues the bill, but your DNSP (Distribution Network Service Provider) owns the poles, the wires, and the Meter. The DNSP is also called your Electricity Distributor.
• Your NMI (National Metering Identifier) names your connection point. Most bills print ten digits, so a portal that asks for eleven leaves you with an NMI with missing 11th digit.
• A Flat Rate tariff, also called Single Rate, charges one price all day. A TOU (Time of Use) tariff splits the day into Peak, Shoulder, and Off-Peak bands.
• A Controlled Load such as off-peak hot water runs on a Dedicated Circuit. It appears in your Smart Meter Data on a secondary import register, typically E2, and never on B1.
• The B1 Meter Register is always your solar export. E1 is a grid import register, and where a meter has more than one E-register, E1 is almost always the main register.
• Your Solar Feed-In Tariff (Solar FiT) credit pays for exported energy. The Victorian Government deregulated the rate from 1 July 2025, so retailers now set their own.

Your Electricity Retailer and Your Electricity Distributor

Your bill comes from your Electricity Retailer. The retailer sets your tariff rates, issues the bill, and takes your payment. Retailers active in Victoria include AGL, Origin Energy, EnergyAustralia, and Powershop.

Your Electricity Distributor is a different company. It is also called your DNSP, short for Distribution Network Service Provider. The DNSP owns and operates the poles and the wires that serve your property.

Most bills name the DNSP only in the faults and emergencies line — for example, "Faults or emergencies: Powercor on 13 24 12". That one line tells you which company to contact for the jobs your retailer cannot do.

Your NMI — National Metering Identifier

Your retailer prints your NMI (National Metering Identifier) on the first page of most bills. Some retailers label it "National Metering Identifier (NMI)" and some label it "NMI Number". The NMI names your connection point, not your account and not any physical Meter.

Your DNSP registers the NMI, and the NMI stays with the property. It does not change when you switch Electricity Retailer, and it does not change when an electrician replaces the Meter.

Why Do Some Forms Need the Full 11-Digit NMI Number?

The 11th digit is a check digit. A standard calculation derives it from the first ten digits. A system can therefore test those ten digits for a typing error before it accepts them.

• Smart meter portals run by your DNSP: some portals test the 11th digit and reject a 10-digit entry. That can block you from your own Interval Data.
• Solar connection applications: an installer may ask for all 11 digits on a grid connection form for your DNSP.
• Energy software and monitoring services: some services validate the NMI at sign-up and refuse a number that fails the test.

If your bill shows ten digits and a form asks for eleven, you do not need to contact anybody. The missing check digit follows from the ten digits already printed on your bill, so you can work it out yourself.

Understanding Your Electricity Charges

The New charges and credits section lists every component of the amount you owe for the billing period. Two components make up most of a residential bill: the supply charge and the usage charges.

The chart shows indicative Victorian rates only. Real rates vary by retailer, by plan, and by DNSP zone. Check the current offers on the Australian Government Energy Made Easy site (Source: Australian Energy Regulator).

What Is the Supply Charge on Your Bill?

The supply charge is a fixed daily fee for the grid connection itself. It applies to every day of the billing period, whatever amount of electricity you use. Bills express it as a rate per day, for example 98.9 cents per day. To weigh that daily charge against usage rates and the Solar FiT across whole plans, see how to weigh up electricity bill components.

Usage Charges — Flat Rate or Time of Use?

Usage charges follow the kilowatt-hours (kWh) of electricity you drew from the grid. Australian residential bills use one of two structures.

Band times vary by retailer, so read your own tariff schedule rather than a generic table. A TOU bill lists each band separately, with the kWh used, the rate in cents per kWh, and the dollar amount. Some retailers now offer free midday hours in place of a cheap Off-Peak band. Our info guide explains which states have free electricity hours.

Controlled Load — Off-Peak Hot Water on a Dedicated Circuit

A Controlled Load is a separately metered Dedicated Circuit. It usually serves an electric hot water service, in-slab heating, or a pool pump. The DNSP sends a signal that allows that circuit to draw power only at set times.

• E1 — a mains-grid import register. Where a meter has more than one E-register, E1 is almost always the main or general register.
• E2 — a secondary mains-grid import register. It typically carries a Controlled Load such as off-peak hot water, and on some plans it carries TOU off-peak or shoulder consumption.
• B1 — solar export. B1 is always the register for electricity your panels send back to the grid, and never a Controlled Load.

Solar generation on site can only supply loads connected to the same register as the solar. A hot water circuit on E2 therefore draws from the grid, and your solar cannot power it, even at midday in full sun. If running hot water on your own solar matters to you, an electrician may need to move that circuit off the Controlled Load.

Which tariff type suits your household is a separate decision from reading the bill. For a plan-by-plan comparison framework, see how to choose an electricity plan for your setup.

Your Solar Feed-in Tariff Credit

If you have rooftop solar, the grid takes the electricity you generate but do not use. Your retailer credits that energy on your bill as a Solar Feed-In Tariff (Solar FiT) credit. It usually appears as "Solar export" or "Standard feed-in tariff", with the kWh exported, the rate, and the credit amount.

Your Smart Meter Data records that exported energy on the B1 register. B1 is always the solar export register. Read it when you want to know how much generation left the property.

The Victorian Government deregulated the solar feed-in tariff from 1 July 2025. The Essential Services Commission no longer sets a mandated minimum rate, and each retailer now sets its own rate (Source: Essential Services Commission Victoria). As of 2026, published Victorian flat-rate offers sit in a wide band of roughly 2 to 15 cents per kWh.

The Meter Details Section on Your Bill

Towards the back of most Australian bills sits a Meter Details table. It shows the Meter reads behind your charges. Each row gives a meter serial number, a read type, a rate description, the start and end reads, and the total kWh.

That table links the lines on your bill to the register codes in your Smart Meter Data.

Rate descriptions differ between retailers, so match the codes printed on your own bill rather than assuming every property looks alike. The Read Type column tells you whether a read was measured (Actual) or calculated (Estimated). An estimated read can produce a correction on a later bill. For a full account of register codes, see how to interpret your smart meter data.

Downloading Your Smart Meter Data

Your bill totals one billing period. Your Meter records a reading every 30 minutes, every day of the year. Under the National Electricity Rules, both your DNSP and your Electricity Retailer must supply that Interval Data to you. The format is NEM12 CSV, the standard AEMO defines.

• What you need: your full 11-digit NMI Number and a login for your DNSP customer portal.
• What you get: a NEM12 file, holding one row of readings per day for each Meter Register.
• Why it tells you more than the bill: half-hourly readings show when you use power, not only how much.

Each DNSP runs its own portal, and the steps differ. For the walk-through, see how to download your Smart Meter Data. Once the file is on your computer, our free NEM12 Smart Meter Data Analyzer charts it in your browser. You can also open NEM12 data in a spreadsheet.

Try our NEM12 Smart Meter Data Analyzer Tool

Energy Assessments Based on Your Bill and Meter Data

Once you can read the bill and your own Interval Data, you can see where your electricity goes. An energy assessor works from those same two sources to right-size solar, batteries, and tariffs for one particular household.

If you would rather have a professional turn all of this into a clear, costed plan for your home, find out more about how our Energy Assessments can help you.

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Frequently Asked Questions

• What is a DNSP? A DNSP (Distribution Network Service Provider) owns and operates the poles and wires in your area. It is also called your Electricity Distributor, and the five Victorian DNSPs are Powercor, AusNet, CitiPower, Jemena, and United Energy.
• Why does my bill show two company names? One name is your Electricity Retailer, the company you pay. The other is your DNSP, the company that runs the local electricity network.
• What is an NMI and where do I find it? Your NMI (National Metering Identifier) appears near the supply address or the Meter Details section of your bill. It names your connection point and stays with the property when you change retailer.
• Why do I need the full 11-digit NMI? The 11th digit is a check digit. Some DNSP portals and solar connection forms test it and reject a 10-digit entry. An NMI with missing 11th digit is normal on bills, and the check digit follows from the first ten digits.
• Is my NMI Number the same as my account number? No. Your account number belongs to your Electricity Retailer and changes when you switch. The NMI Number belongs to the connection point and does not change.
• What is the difference between Flat Rate and Time of Use? A Flat Rate tariff, also called Single Rate, charges the same amount per kWh at every hour. A TOU (Time of Use) tariff charges different rates in Peak, Shoulder, and Off-Peak bands.
• What does Peak mean on a Time of Use bill? Peak is the highest-priced band on a TOU tariff, and it typically covers weekday daytime and early evening. The exact hours vary by retailer, so check your own tariff schedule.
• What does Off-Peak mean on a Time of Use bill? Off-Peak is the lowest-priced band on a TOU tariff, and it typically covers overnight hours and sometimes weekends. The exact hours vary by retailer.
• What does Shoulder mean on a Time of Use bill? Shoulder is a mid-priced band between Peak and Off-Peak. It appears on some TOU plans and not on others, and its hours vary by retailer.
• What is the daily supply charge on an electricity bill? The supply charge is a fixed daily fee for the grid connection itself, applied to every day of the billing period. It does not change with the amount of electricity you use.
• What does Controlled Load mean on my bill? A Controlled Load is a Dedicated Circuit, usually electric hot water, that the DNSP allows to draw power only at set times. Your retailer bills it at a discounted rate on its own line.
• Which Meter Register is my Controlled Load on? A Controlled Load is a grid import, so it appears on a secondary import register, typically E2. It never appears on B1.
• What does the B1 register mean? B1 is always solar export — the electricity your panels generate and send back to the grid. It is never an import register and never a hot water circuit.
• What does the E1 register mean? E1 is a mains-grid import register. Where a meter carries more than one E-register, E1 is almost always the main or general household register.
• What does the E2 register mean? E2 is a secondary mains-grid import register. It usually carries a Controlled Load such as off-peak hot water, or TOU off-peak and shoulder consumption.
• Can my solar power my controlled-load hot water? No. Solar can only supply loads on the same register as the solar, so a hot water circuit on E2 draws from the grid even at midday.
• How do I read my Solar FiT credit? Look in the credits section for a line such as "Solar export" or "Standard feed-in tariff". It shows the kWh exported, the rate, and the dollar credit. Since 1 July 2025, Victorian retailers set the Solar Feed-In Tariff rate themselves.
• Who sets the solar feed-in tariff in Victoria? The Essential Services Commission set a mandated minimum until 1 July 2025. Since then each Electricity Retailer sets its own rate, so published offers vary widely.
• How do I download my Smart Meter Data? Log in to your DNSP customer portal with your full 11-digit NMI, then request the Interval Data download. The file arrives in NEM12 CSV Format.
• Why do my bill totals not match my Smart Meter Data exactly? Estimated reads, rounding across the billing period, and the way retailers apply TOU bands can all produce small differences. The Meter Details table is the cleanest point of comparison.

Try our NEM12 Smart Meter Data Analyzer Tool

Glossary

AEMO

Australian Energy Market Operator — the body that administers the National Electricity Market and defines and maintains the NEM12 specification.

AER

Australian Energy Regulator — sets the Better Bills Guideline that mandates how bills must be presented.

B1

In the NEM12 Format, the Meter Register code for Solar Export — electricity generated on site and fed back to the grid, typically measured in kWh.

Check Digit

The 11th digit of a full NMI — calculated from the first ten digits to detect transcription errors; some DNSP portals require it. Also called a 'Checksum'.

Controlled Load

A separately metered circuit controlled by a signal from the DNSP. These circuits typically contain a single specific appliance or type of appliance - eg. an Electric Hot Water Service (and historically Air-Conditioners or Electric Slab Heating). They are typically billed at a discounted rate and often run only during off-peak hours. They appear on a separate Meter Register on an Electricity Bill. See also: Dedicated Circuit.

CSV

Comma-Separated Values — a plain text file in which each row is a record and fields are separated by commas.

Dedicated Circuit

The physical wiring and breaker serving a Controlled Load device, isolated so the DNSP can independently control supply. See also: Controlled Load.

Distribution Network Service Provider

See DNSP.

DNSP

Distribution Network Service Provider - the company that owns and operates the physical poles and wires of the local electricity network, and usually provides the smart meter data portal. Not the same as your Electricity Retailer. See also: Electricity Retailer.

E1

In the NEM12 Format, the Meter Register code (or NMI Suffix) for the sole/main/primary mains grid import channel — electricity drawn from the network. Where there is No (Solar) Generation on site, this is the Total Consumption. Typically measured in kWh.

E2

In the NEM12 Format, the Meter Register code (or NMI Suffix) for a secondary mains grid import channel — typically controlled-load or off-peak consumption such as dedicated hot water. Present only where that tariff exists.

Electricity Distributor

See DNSP.

Electricity Retailer

The company that sells electricity to the consumer, issues the bill, and manages the account. Not the same as your DNSP (Distribution Network Service Provider) which owns and operates the network. See also: DNSP.

ESC

Essential Services Commission — the Victorian energy regulator; sets and reviews tariff and FiT policy.

Flat Rate

A single price per kWh that applies at all times of day (and all days of the week). Also called Single Rate.

Interval Data

Energy readings recorded at fixed time steps — typically every 30 minutes (but sometimes 5 or 15 minutes on newer meters) rather than as a single billing total. This allows charging different Tariffs at different times of day or days of the week. See also: Time-of-Use (TOU) Tariff.

kW

KiloWatt — the standard unit of (Electrical) Power: 1,000 Watts of Power used continuously for one hour is equivalent to 1000 Watt-Hours or 1 KiloWatt-Hour of Energy. Power is not an Amount of Energy but a Rate of Energy Transfer. See also: kWh.

kWh

KiloWatt-Hour — the standard unit of (Electrical) Energy: 1,000 Watts of Power used continuously for one hour is equivalent to 1000 Watt-Hours or 1 KiloWatt-Hour. NEM12 CSV records Electricity Use in kWh. See also: kW.

Meter

The physical device at the premises that measures and records electricity import and export.

Meter Register

See NMI Suffix.

National Metering Identifier

See NMI.

NEM

The Australian National Electricity Market — the interconnected electricity grid covering Queensland, New South Wales, Victoria, South Australia, Tasmania and the ACT. Western Australia and the Northern Territory operate separate grids.

NEM12

The AEMO file format (version 12) for exchanging Interval Data from Smart Meters across the Australian National Electricity Market (NEM). NEM12 Format records the Amount of Energy per Time Interval in kWh. And also other types of data, using specific types of labelled rows or records (100, 200, 300, 400, 900) to record different types of data. This makes it a 'Semi-Structured' 'Non-Tabular' Format. See also: AEMO, NEM, kWh, Semi-Structured, Non-Tabular.

NEM12 CSV

A NEM12 File stored as comma-separated values — the form most DNSP and retailer portals distribute. See also: NEM12, CSV.

NMI

National Metering Identifier — the unique 10-digit identifier for an electricity connection point (11 with the Check Digit), permanent to the property. Note that the electricity connection point identified by the NMI, typically has multiple NMI Suffixes, and can have multiple Physical Meters. See also: Check Digit, NMI Suffix.

NMI Suffix

In the NEM12 Format, the short two-character code (E1, E2, E3, B1, B2, Q1, K1) identifying a specific Meter Register for recording electricity flows on the mains electricity connection identified by that NMI — also called the Meter Register or Register Code. See also: NMI, NEM12.

NMI with missing 11th digit

A 10-digit NMI as commonly printed on bills — the 11th check digit has been omitted and may need to be calculated for portal access. See also: NMI, Check Digit.

Non-Tabular

Data that does not fit a single consistent grid — in NEM12's case because of its semi-structure, hierarchy and mixed-record layout.

Off-Peak

The lowest-priced time period in a Time-of-Use (TOU) Tariff — typically overnight and sometimes weekends. In current usage refers to the Time electricity is imported on a Meter Register and at Other Times, the import rate on that Same Meter Register might be different. It can also currently refer to Dedicated Circuits / Controlled Loads that are only permitted to draw power at set Off-Peak times. And historically, before Smart Meters, only the latter could receive an Off-Peak Rate. See also: Time-of-Use (TOU) Tariff, Controlled Load, Dedicated Circuit.

Peak

The highest-priced time period in a Time-of-Use (TOU) Tariff — typically weekday daytime and early evening. See also: Time-of-Use (TOU) Tariff.

Semi-Structured

A data format that follows strict syntactic rules (e.g. comma separation, defined record codes) but does not enforce a consistent column schema across all rows. NEM12 is a Semi-Structured Format. See also: NEM12.

Shoulder

A mid-priced period in some (but not all) TOU Tariffs, between Peak and Off-Peak. See also: Time-of-Use (TOU) Tariff.

Single Rate

See Flat Rate.

Smart Meter Data

Electricity import and export readings recorded by a digital interval meter at regular intervals. In Australia, typically supplied in NEM12 CSV Format with 30 Minute Intervals. See also: NEM12 CSV.

Solar Feed-in Tariff (FiT)

The credit paid (in cents per kWh) by your Electricity Retailer for solar electricity you export to the grid (B1 Meter Register). In Victoria, a minimum rate was historically set annually by the Essential Services Commission (ESC). However, since July 2025, the ESC no longer sets a minimum, and Electricity Retailers are free to pay a Market Rate.

Time of Use

See Time-of-Use (TOU) Tariff.

Time-of-Use (TOU) Tariff

A tariff with different prices at different times of day or days of the week (Peak, Shoulder, Off-Peak).

TOU

See Time-of-Use (TOU) Tariff.

Try our NEM12 Smart Meter Data Analyzer Tool