/ Business energy guide
How to spot overcharges on a business energy bill
A commercial energy bill stacks six or seven different charges on top of each other. Each is calculated separately, and each can be wrong independently of the others. Here is how to read one properly.
Guide reviewed September 2026 · Business-Utility.com
Start with the meter reading
Every other figure is derived from consumption, so an estimated read poisons the whole bill. Find the read type on your statement — actual, customer or estimated — and compare the closing reading against the meter itself. Where a period has been estimated and later corrected, check the catch-up bill has not applied current unit rates to historic usage.
- Check whether the read is actual or estimated
- Compare the closing read to the physical meter today
- Confirm the MPAN (electricity) or MPRN (gas) belongs to your premises
- Look for a reading that jumps then corrects — a sign of a long estimated run
Unit rate and standing charge against the contract you signed
Pull out the contract acceptance or renewal letter and compare the pence-per-kWh and daily standing charge printed on the bill against it. Rates should not move mid-term unless the contract expressly allows a pass-through change. If your fixed term has ended, you may have rolled onto deemed or out-of-contract rates, which are typically far higher than anything you would be offered on renewal.
- Unit rate on the bill matches the rate on the contract
- Standing charge matches, per meter, per day
- The contract end date on the bill matches your paperwork
- No silent switch to deemed or out-of-contract rates
VAT: the 20% default that should sometimes be 5%
Business energy is normally charged at the standard rate, but qualifying low-usage supplies and premises used mainly for charitable or domestic purposes attract the reduced rate. Suppliers apply 20% by default unless a declaration is held. The gap is substantial and is commonly correctable for past periods as well as future ones — see HMRC's published guidance on fuel and power for the qualifying criteria.
Climate Change Levy and other non-commodity charges
CCL is charged per unit of energy used, and where a supply qualifies for the reduced VAT rate the levy often should not apply at all. Below the commodity cost sit further pass-through charges — network, balancing and policy costs. These are legitimate, but on a fixed contract they should not be added separately unless the contract says so.
- CCL charged on a supply that qualifies for relief
- Pass-through charges added to a fully fixed contract
- Duplicate charges across a bill covering multiple sites
Capacity charges on half-hourly sites
Larger electricity sites are billed on an agreed available capacity (kVA) as well as on what they use. Businesses that have changed equipment, moved production or become more efficient are frequently paying for capacity far above their peak demand. Reviewing the maximum demand data and, where appropriate, asking the network operator to reduce agreed capacity is a permanent saving, not a one-off refund.
Back-billing and how far back you can go
Ofgem rules prevent suppliers from charging microbusinesses for energy used more than twelve months earlier where they failed to bill correctly. Separately, billing errors under contract can often be pursued for several years. Keep every bill: a reclaim is only as strong as the paper trail behind it.
Frequently asked questions
- How far back can a business reclaim an energy overcharge?
- It depends on the type of error. VAT corrections are commonly reclaimable for up to four years, and billing errors under contract can often be pursued for up to six years, subject to the supplier's position and the evidence.
- When does a business pay 5% VAT on energy instead of 20%?
- The reduced rate applies to qualifying low-usage supplies and to premises used mainly for charitable or domestic purposes. Suppliers commonly default to 20%, so a business that qualifies must declare its status to have the rate corrected.
- Can a supplier back-bill me for years of unbilled energy?
- Ofgem's back-billing rules prevent suppliers charging microbusiness customers for energy used more than 12 months earlier where the customer was not previously billed correctly. A catch-up bill beyond that window should be challenged.
- What is the Climate Change Levy?
- CCL is a tax on business energy use. Certain supplies are excluded or relieved — including qualifying low-usage supplies, charitable non-business use and sites covered by a Climate Change Agreement — so it is sometimes charged in error.
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