Why Your Gas Bill Looks Higher Than Expected

If your gas bill is higher than expected — or just never seems to match what you’ve used — you’re not alone. It’s one of the most common smart meter complaints in the UK. Here’s what’s likely causing it, and what you can do.

Six reasons your gas bill might be higher than expected

1. Your supplier has been estimating your readings

If your smart meter hasn’t been sending readings automatically, your supplier may have been guessing — and then corrected the bill when a real reading came through. This can cause a sudden spike that looks wrong but is technically accurate.

The fix: submit a manual reading immediately and ask your supplier to reconcile the account.

2. Your meter is recording in the wrong units

Gas meters measure in either cubic metres (m³) or hundreds of cubic feet (ft³). If your supplier is applying the wrong conversion factor, your bill could be significantly inflated. This is more common than most people realise.

→ Use our gas meter reading to kWh calculator to check your own figures

3. You’ve moved to a higher tariff without realising

If your fixed-rate deal ended, you may have been automatically moved to a standard variable tariff — which is almost always more expensive. Check your paperwork or online account for any tariff change notices.

4. A meter replacement caused a billing reset

When a meter is replaced, the opening read should match the closing read of the old meter. If it doesn’t, you could be billed for usage that was never yours.

→ Gas meter replaced — why your bill changed

5. Your direct debit was recalculated

Energy suppliers review direct debits periodically. If yours was increased, it may be based on projected usage rather than actual usage — especially common after winter. It doesn’t always mean you owe money.

6. There’s a genuine fault with your meter

Smart meters can develop faults that cause them to over-record usage. This is relatively rare but it does happen. If you’ve ruled out everything else, you have the right to request a meter accuracy test — your supplier must carry this out.

What to do if your bill looks wrong

Start by working out whether the bill is based on estimated or actual readings. You can do this by:

Checking your meter display against what’s on the bill
Looking for an “E” next to the reading on your bill (E = estimated)
Using our calculator to verify the kWh figure yourself

If the numbers don’t stack up, you have the right to dispute the bill. Your supplier must investigate and respond within a reasonable timeframe.

Check your bill figures with the Bill Checker →

Ready to dispute?

If you’ve identified a problem and your supplier isn’t helping, a formal written complaint is your next step. It creates a paper trail and triggers your supplier’s official complaints process — which has regulatory deadlines they must meet.

Generate a complaint letter in minutes →

Still not sure what’s causing it?

Run a quick Health Check and we’ll help you identify the problem.

Start your free Health Check →

Related help:

All advice on SmartMeterHelp is independent. We’re not affiliated with any energy supplier.