Business energy bills explained: charges, tax and meters

Start with the meter, dates and two core charges

The Ofgem supply and complaints framework discussed here applies to Great Britain; Northern Ireland has a separate energy regulatory framework.

Confirm that the bill belongs to your legal business and the correct premises. Check the meter serial number and supply identifier against your records. A supply identifier identifies the connection; it is not the same thing as the physical meter's serial number. Multi-unit buildings and recently divided premises make this distinction particularly useful.

Next, check the period and whether the readings are actual, customer-supplied or estimated. Look for a meter exchange or opening reading if the premises or supplier changed. Electricity consumption is measured in kilowatt-hours; gas meter units are converted to kilowatt-hours using the calculation shown on the bill. Do not compare raw gas meter movement directly with billed energy without that conversion.

The unit rate applies to energy used. The standing charge applies over time, commonly for each day, even where consumption is low. Comparing unit rates alone overlooks the standing charge and other contract elements. Use annual consumption and the same period when discussing alternative terms, rather than comparing bills covering different seasons.

If your contract has multiple time bands, make sure the relevant consumption is assigned to each band. Ask the supplier to explain unfamiliar registers or time periods. A correct total reading does not necessarily prove that the split across charging bands is correct.

Understand VAT and the dated change ahead

Business fuel and power are normally subject to standard-rate VAT, currently 20%. Qualifying use can receive relief: domestic use, charity non-business use and supplies within the small-quantity rules are examples. Being a charity does not make every activity non-business, and being a small business does not itself settle the VAT treatment.

The small-quantity tests include supplies averaging no more than 33 kWh of electricity a day or 145 kWh of piped gas a day. Where at least 60% of a mixed supply is qualifying use, the whole supply receives the qualifying treatment; below that, apportionment may be needed. Ask about the appropriate customer certificate and retain the evidence supporting it.

As of 9 September 2026, qualifying electricity and gas generally use the reduced 5% rate. HMRC guidance updated on 8 September 2026 states that qualifying electricity supplies in Great Britain will temporarily be zero-rated from 1 October 2026 to 31 March 2027. Qualifying electricity in Northern Ireland remains at 5%, and the announcement does not change which uses qualify.

For bills crossing a rate-change date, ask the supplier how the tax rules that apply have been applied. Do not manually replace the VAT on an invoice without obtaining the appropriate corrected document. An accountant can help with mixed use, evidence and any recovery of input tax.

Check the Climate Change Levy separately

Climate Change Levy is a tax on relevant business energy supplies, separate from the supplier's commercial unit price. From 1 April 2026, the published main rate for electricity and gas is 0.801p per kWh. This is a statutory tax rate, not an energy offer. Check the consumption dates where an invoice spans a rate change.

Domestic use, charity non-business use and qualifying small supplies can be outside the levy. Businesses holding a qualifying climate change agreement can receive reduced rates under the scheme; the published reductions for 2026 are 92% for electricity and 89% for gas. Eligibility and the required certification matter. Do not assume a general environmental commitment creates entitlement.

VAT is calculated on the taxable value including levy where applicable. That can explain why the VAT amount is not simply the percentage applied to the basic energy subtotal you first noticed. Ask the supplier to identify the calculation base if it is not clear from the invoice.

Keep levy declarations and VAT-use certificates distinct in your records even where they rely on related information. Review them when premises use changes. A workshop adding residential accommodation, for example, needs an assessment of actual supply and use rather than an unchanged declaration carried forward automatically.

Decode network and system costs

Electricity needs transmission, local distribution and system balancing as well as the energy itself. Bills or contract schedules may refer to transmission network use of system, distribution use of system and balancing services use of system, commonly abbreviated to TNUoS, DUoS and BSUoS. These are different functions and may be recovered in different ways.

The national system operator publishes transmission and balancing charging information, while local distribution charges depend on the network and relevant methodology. The amount shown on your bill also depends on how your supply contract recovers those costs. A published network tariff is not necessarily identical to a single retail bill line.

Ask for the contractual basis, the period and the calculation if a pass-through item changes. Avoid treating every unfamiliar abbreviation as an extra discretionary supplier fee. Equally, a genuine third-party cost does not remove the need for the supplier to explain how the contract allows it to be charged.

Find out what fixed actually covers

A contract can fix specified energy components while allowing other costs to vary. Pass-through terms describe charges recovered as they change rather than being absorbed within a fully fixed price. The word fixed in a sales conversation therefore needs to be read alongside the detailed offer and Principal Terms.

Before agreeing, ask which components can change, what triggers a change and where the calculation is defined. Request a written explanation using the actual contract. If the answer refers to third-party costs generally, ask which categories are included. Do not assume a heading on the first page answers the question.

If a bill rises during an existing contract, separate greater consumption, a longer billing period, corrected estimates, taxes and pass-through changes. That analysis helps you identify whether the disputed issue concerns calculation or what was disclosed at sale. Keep any sales correspondence that describes the price as fixed.

Our broker commission guide explains another cost that may sit inside contract charges. Commission disclosure and pass-through disclosure address different questions, so obtaining one does not settle the other.

Capacity and metering need site-specific questions

Some electricity sites have an agreed supply capacity, measured in kVA, with associated capacity charges and possible excess-capacity charges. This is different from energy consumed in kWh. Ask which connection agreement and tariff apply to the site, particularly after adding machinery or taking over premises with a previous occupant's configuration.

Do not reduce an agreed capacity simply because recent consumption was low. Peak demand, equipment starting loads and future operations need technical consideration. Discuss changes with the relevant network and a competent electrical adviser. The consequences concern the connection as well as the bill.

Meter operation and data services may be covered through the supplier or under separate agreements. Half-hourly data and settlement changes do not make every site's contract identical. Establish who provides each service, who bills it, and whether an existing agreement continues when the energy supplier changes.

Keep metering documents alongside the supply contract. If an invoice appears duplicated, compare the service, period and responsible party before assuming both relate to the same charge. A meter rental and a separate data service can have similar descriptions while covering different functions.

Correct an estimate and prepare the next enquiry

Photograph a safe, accessible meter reading and submit it through the supplier's approved route. Include the date, meter serial number and relevant registers. Do not open sealed or electrical equipment. Ask whether a corrected bill will replace the estimate and how any previous balance will be adjusted.

If the supplier refuses or the correction does not resolve the issue, make a written complaint with the original bill, reading evidence and chronology. Micro-business back-billing protection can be relevant to certain older unbilled usage, but it does not automatically remove properly billed unpaid debt. The energy rights guide explains escalation.

Once an error is corrected, compare the replacement invoice with the account balance rather than checking only the new document. Confirm whether the original charge was reversed, how payments were allocated and whether the next collection changed. Keep both versions so the adjustment remains understandable when the accounts are reconciled later.

What to do next

Gather the following before requesting an explanation or new terms:

• Recent bills covering comparable periods.
• Annual consumption and each relevant meter register.
• Principal Terms, contract end date and metering agreements.
• Actual reading photographs and meter identifiers.
• VAT-use and levy declarations where applicable.
• A list of the specific lines or calculations you want explained.

Use those records for a business energy enquiry. The named specialist partner can discuss your requirements, while the supplier remains responsible for explaining and correcting its own bill.