Why is my British Gas bill so high?

Every British Gas bill has two parts. There’s the bit you expect — what you pay for each unit of energy you use. And there’s the standing charge: a fixed daily fee just for being connected to the gas and electricity networks, whether you use any energy or not.

Right now that’s roughly 61p a day for electricity and 31p a day for gas. Add those up and it’s about £335 a year before you’ve boiled a single kettle. That’s why a bill can feel high even in a month you were barely home — the standing charge keeps ticking over regardless.

If you’re on British Gas’s standard variable tariff — the default you end up on if you’ve never actively chosen a deal — your rates follow the Ofgem price cap, which changes every three months.

Ofgem confirmed on 27 May 2026 that the cap would rise 13% from 1 July. For a typical household that’s the annual bill going from £1,641 to £1,862 — about £18 a month extra. The rise wasn’t even across both fuels: gas unit rates went up around 24%, electricity around 5%. So if you heat your home with gas, you’ll have felt this one most.

Want the full picture of what changed and why? See our July 2026 price cap breakdown and calculator.

If British Gas doesn’t have a real meter reading, they estimate your usage — these show up on the bill marked “estimated” or with an “E”. If those estimates were too low for a while, you weren’t actually saving money; you were just building up a gap. When a real reading finally comes in, the catch-up all lands on one bill, and it can look like a sudden spike.

The fix is simple and free: send British Gas an actual meter reading through their app or website. If you have a smart meter that’s lost its connection — which happens after a house move or a firmware update — getting it talking again stops the estimates. For more on how this shows up on the page, see our guide to reading your British Gas bill.

This one sounds obvious but trips a lot of people up because of how direct debits work. You use far more gas heating your home in the cold months than in summer — sometimes three or four times as much. So a December or January bill being much higher than a July one is completely normal, even though nothing about your tariff changed.

It catches people out when they pay by a fixed monthly direct debit, because the payment stays flat while the actual usage swings. A cold snap, a new baby at home, working from home more — any of these can quietly push your real usage above what your payments are covering.

If you signed up to a fixed-rate tariff a year or two ago, your unit rates were locked in for the length of that deal. When it ends, British Gas doesn’t put you on another fix automatically — you roll onto their standard variable tariff, which tracks the Ofgem price cap.

Depending on the deal you were on, that move can be a jump. The bill that arrives after your fix ends can look alarming purely because you’ve gone from a locked-in rate to the current cap rate. If this is you, it’s worth checking whether a new fixed tariff would beat the cap — it often does. Switching takes about 15 minutes, your supply never cuts off, and you can cancel anytime.

Your direct debit isn’t your bill — it’s British Gas’s best guess at your yearly cost, spread evenly across 12 payments so you’re not hit with a huge winter bill all at once. They review it periodically, usually once a year.

If your usage has been higher than they assumed, or the price cap has risen, that review can push your monthly payment up — sometimes by a lot, because they’re also trying to claw back any shortfall that’s already built up. If the new amount looks too high for what you actually use, you can ask British Gas to review it; sending an up-to-date meter reading first strengthens your case.