The short version
General information, not advice
- Each fuel costs what you used × the unit rate, plus a daily standing charge
- VAT is charged per fuel, at today's rates: electricity 0%, gas 5%
- A monthly direct debit is an average across the year, not what that month cost
- Most billing problems come from estimated readings — a photo of your meter settles most of them
The sum on every bill
Electricity and gas are worked out separately, the same way, then added together.
Use nothing for a year and the meter side is £0. The calendar side isn’t: 365 days × 54.83p is £200.13 for electricity, and 365 × 29.68p is £108.33 for gas, at October to December 2026’s cap.
Meter reading (kWh) multiplied by the unit rate, plus the number of days multiplied by the standing charge, equals the cost for that fuel. Then VAT is added at that fuel’s own rate.
Then VAT is added, at each fuel’s own rate, and any credits or support are taken off.
0% VAT on domestic electricity from 1 October 2026 to 31 March 2027: HMRC Revenue and Customs Brief 10 (2026) and SI 2026/987, checked 4 October 2026. Great Britain only; in Northern Ireland the rate is unchanged.
Try it with your own usage
Your annual kWh is on your bill or in your supplier’s app. The boxes start at Ofgem’s typical household. Rates are the cap averages for Great Britain by direct debit — your region’s will differ a little.
Electricity
Gas
An estimate, not a quote. Electricity 26.32p per kWh and 54.83p a day, with no VAT; gas 7.59p per kWh and 28.27p a day before 5% VAT (7.97p and 29.68p with it). Source: Ofgem, price cap, October to December 2026, checked 25 September 2026.
Where the money goes
The same typical dual-fuel bill, split by electricity, gas and the VAT on top of both, at October to December 2026’s rates.
Electricity £858 (50%), gas £824 (48%), and VAT £41 (2%) — a typical dual-fuel bill of £1,724 a year at October to December 2026’s rates.
Of every £10: £4.98 electricity, £4.78 gas, 24p VAT.
Reading the bill in front of you
Every supplier lays its bill out differently, but the same eleven things are on all of them. Step through it to see what each part is and what to check.
See it step by step
Reading the bill in front of you
Step 1 of 14
Every bill is the same sum
Every energy bill, from every supplier, is the same sum underneath. Once you can see the sum, you can check the bill.
+ days × standing charge
= cost of each fuel
Work it out for electricity and gas separately, add VAT at each fuel’s rate, then add the two together.
This example covers 1 to 31 October 2026. Press Next, or Play to watch it all.
Figures from the Switch4Good guide, Understanding your energy bill, checked 4 October 2026: the bill is an invented example priced at the price-cap rates for October to December 2026. 0% VAT on domestic electricity from 1 October 2026 to 31 March 2027: HMRC Revenue and Customs Brief 10 (2026) and SI 2026/987, checked 4 October 2026. Great Britain only; in Northern Ireland the rate is unchanged.
It shows this month (Oct 2026), at the cap rates in force (October to December 2026). The account is not real.
If you think the bill is wrong
Take a photo of the meter showing today’s reading, then compare it with the bill: the supply number, the reading and its type, the dates, and the rates. If something doesn’t match, send the supplier the photo and ask for a corrected bill. If they don’t sort it out, raise a formal complaint. After eight weeks without a resolution, or sooner if the supplier issues a deadlock letter, you can refer the complaint to the Energy Ombudsman, which is free and independent. If you’re struggling to pay, tell the supplier: they have to consider payment plans and support, and you may qualify for the Warm Home Discount.
Sources, checked 25 September 2026: Ofgem, changes to the price cap, October to December 2026 (unit rates, standing charges and VAT) · GOV.UK, Warm Home Discount. The figures above are Ofgem’s price cap for the quarter currently in force. Switch4Good Limited is a commercial business and not a charity. General information, not advice.
Your energy bill checklist
Twelve things to look at on the bill in front of you.
- Find the unit rate and the standing charge for each fuel on the bill.
- Check whether the reading the bill is based on is an actual reading or an estimate.
- Compare the reading on the bill with what the meter shows today.
- Check the MPAN (electricity) and MPRN (gas) on the bill belong to your address.
- Check which tariff you are on and whether it has an end date.
- Check whether an exit fee applies if you leave before that date.
- If you are on a standard variable tariff, check the rates against the cap for your region.
- Check the VAT rate applied to a domestic supply.
- Check any credits, discounts or government support are shown.
- Check the billing period runs from where the last one stopped, with no gap and no overlap.
- Check your direct debit against what the bill says you are actually using.
- Check whether anyone in the household would qualify for the Priority Services Register.
Common questions
Why is my bill higher even though I used less energy?
Your unit rate or standing charge may have increased, or your bill may include catch-up from previous underestimates.
What's the difference between kW and kWh?
kW is power (how fast energy is used). kWh is energy over time (what you're billed for).
My smart meter is installed — why am I still getting estimated bills?
The meter may not be communicating properly, or the supplier may not be receiving readings. Ask them to confirm communications status.
Why is gas usage sometimes shown in m³ and sometimes in kWh?
The meter measures volume; billing uses energy (kWh). Suppliers convert it using standard factors.
Can I challenge a direct debit increase?
Yes. Ask for the calculation and usage assumptions. You can request adjustments if it's clearly excessive.
What should I do when switching supplier?
Take meter readings on switch day and keep photos. This helps if there is a dispute about closing readings.
How quickly must a supplier fix a billing error?
Timeframes vary, but you can request a formal complaint and escalate if delays continue.
Who can help if my supplier isn't resolving it?
Start with the supplier complaints process. If unresolved, you can refer it to the Energy Ombudsman after eight weeks, or sooner if the supplier issues a deadlock letter.
Switch energy
Compare regulated UK energy tariffs. At least 50% of eligible commission goes to your chosen cause.