Why business energy bills are quoted ex-GST (and why it matters when comparing)

Business rates are usually shown GST-exclusive, household rates GST-inclusive. Compare the two directly and you will be about 10% out.

The same rate, two different numbers

A household electricity bill in Australia shows rates with GST already included. A business bill usually does not: line items are shown GST-exclusive, with a single GST line added at the end.

That means 25c/kWh on a business bill and 25c/kWh on a household bill are not the same price. The business rate is really 27.5c once GST is added. Compare the two figures side by side without adjusting, and every conclusion you draw is out by roughly 10%.

This trips up more comparisons than it should, including automated ones. It is a quiet error because nothing looks wrong — the numbers are all plausible, they are just measured on two different bases.

Which basis should you compare on?

If you are registered for GST and claim input tax credits, the GST you pay on energy is not a real cost to you: you get it back. The number that matters for your business is the ex-GST one, and that is the basis you should compare and budget on.

If you are not registered for GST, the inclusive figure is your real cost, because you cannot claim the credit.

The important thing is not which basis you pick, but that both sides of any comparison use the same one. Mixing them is how a plan that is genuinely dearer ends up looking cheaper.

Where the confusion usually bites

Comparing a quote to your current bill: A retailer quoting ex-GST against a bill you are reading inc-GST will look about 10% cheaper than it is. Check the basis on both before believing the gap.
Comparison tools built for households: They generally assume inc-GST throughout, because that is how residential rates are published. Feed business rates in and the output is wrong.
Regulator-published rate data: The AER publishes reference pricing GST-EXCLUSIVE. Anything built on that data has to gross it up before showing a household an inclusive figure — an adjustment that is easy to miss.
Your own budgeting: If you forecast on inc-GST figures but claim the credits back, you will systematically over-provision for energy by about a tenth.

What we do

For business comparisons we default to the ex-GST view, because that is the number a GST-registered business actually bears, and we read the basis off your bill rather than assuming. If your line items are ex-GST we record that and adjust so the reconstruction of your bill still reconciles against the inclusive total printed on it.

For households we do the reverse: the regulator publishes rates ex-GST, so we gross up usage, supply and controlled-load rates by 10% before anything is shown. Feed-in tariffs and some fees are not grossed, because GST does not apply to them the same way.

You can switch the whole results view between inc-GST and ex-GST, so you are never comparing across two bases by accident.

Frequently asked questions

Does GST apply to electricity in Australia?

Yes, at 10%, the same as most goods and services. Household bills show it built into the rates; business bills usually show it as a separate line at the end.

Can my business claim the GST on its energy bills?

If you are registered for GST and the energy is used in carrying on your business, you can generally claim the GST as an input tax credit. That is why ex-GST is the meaningful basis for comparison. Confirm your own position with your accountant.

Is the solar feed-in credit on my bill GST-inclusive?

Feed-in credits are treated differently from the charges on the bill, and the treatment depends on whether you are registered for GST and whether the export is part of your enterprise. Do not assume it carries GST the same way your usage charges do.

Why does the regulator publish rates ex-GST?

The Consumer Data Right energy dataset publishes reference pricing on a GST-exclusive basis. Any tool built on that data must add GST before showing a household an inclusive rate — if it does not, its figures run about 9% low.

General information only, current at the time of writing. Not financial advice. Rebate schemes and rules change; always confirm details with your retailer or state government energy site.