Why is my business energy bill higher than usual?
The usual causes are a catch-up after an estimated bill, your contract ending and moving to a pricier rate, higher usage, a longer billing period, or network charges. Compare the unit rate, standing charge and kWh used against your last bill to find which one changed.
A bill jump rarely has one cause. Work through the checks below in order; the first three explain most surprises.
1. Was the last bill an estimate?
If earlier bills were estimated too low, the next accurate reading triggers a catch-up. Compare readings, not totals. See how to correct an estimated bill.
2. Has your contract ended?
When a fixed term ends, you may roll over or drop onto out-of-contract or deemed rates, which Ofgem says are usually dearer than fixed-term deals. Moneysupermarket's October 2026 snapshot (a comparison site, so indicative only) put average out-of-contract electricity at 40.0p per kWh against 28.4p for a microbusiness fixed deal.
Example: a shop using 2,500 kWh a month pays an extra 2,500 × (£0.400 − £0.284) = 2,500 × £0.116 = £290 a month after the switch to out-of-contract rates. Our out-of-contract cost calculator works yours out. See also why prices rise at renewal.
3. Did you use more?
Cold snaps, a new fridge, an extra shift, a faulty thermostat or equipment left on overnight all push up kWh. Compare the kWh figure on this bill with the same period last year.
4. Is the billing period longer?
A bill covering 62 days looks bigger than one for 30. Check the dates and the standing charge days; standing charges are paid daily whether you use energy or not.
5. Network and policy costs
Part of your price is passed on from network and policy costs. If your contract is pass-through, these can change mid-contract. Transmission charges (TNUoS), confirmed by the National Energy System Operator, rose by around 60% on average for businesses from April 2026, according to one supplier's analysis. Learn more in non-commodity charges explained.
6. Tax and capacity charges
Check the VAT rate (20% standard; 5% only for qualifying use) and Climate Change Levy, currently 0.801p per kWh. Half-hourly sites can also see capacity charges climb; see kVA charges.
7. Meter or billing error
A wrong multiplier, a swapped meter or a faulty reading can inflate usage. If the figures look impossible, ask for a meter check.
What to do
- Ask for a bill breakdown by period, rate and reading.
- Send a fresh dated reading.
- If the cause is your rate, negotiate or switch; there is no termination fee when out of contract.
- If you think the bill is wrong, follow our guide to disputing a high business energy bill.
Quick diagnostic table
| Symptom | Likely cause |
|---|---|
| Unit rate changed | Contract ended or pass-through charges moved |
| kWh much higher, rate same | Real extra use, or earlier under-estimate |
| Same usage, bigger total | Longer period, tax or capacity charge |
| Reading marked E | Estimated bill; send a reading |
Match your bill to a row before you phone the supplier. It makes the conversation shorter and more productive.
Next steps
Keep the last 12 bills together so patterns show up quickly, and diarise your contract end date.
Sources
General information only. Energy prices, rules and supplier terms change; check the latest position with your supplier, Ofgem or the Energy Ombudsman before you act.