An easy fix available to both new and exisiting customers can make British Gas 14% cheaper. But it is limited to 20,000 switches and done on a first come, first served basis. Money saving expert Martin Lewis has warned that millions are still overpaying for energy, despite Collective Switches - a way energy firms offer deals that undercut their own public deals. Mr Lewis highlighted the British Gas Collective, which is locked in the maximum rate so as not to increase for a set time.

He also told Brits that the energy bill price cap is expected to decrease, with those on most existing fixes seeing their rates slashed as well. If on a firm's standard tariff, customers are on the price cap, which is "pants", according to Martin. So the British Gas Collective is one of two fixes he has recommended, along with a cheaper on from a little firm called Fuse.

Mr Lewis wrote: "One of my Collective conditions was as much detail on the post-April rates as possible.

"So the British Gas tariff is 14% cheaper than today's Price Cap and should stay that much cheaper (or likely slightly more) once it drops."

The fix has an early exit fee of £50/fuel. A smart meter is not needed, and it is for dual fuel/electric or gas only.

The deal uses direct debit and pay on receipt of bills.

Mr Lewis wrote: "As we write, this is currently cheaper on typical usage than all open market fixes, averaging 14.1% less (including MSE cashback) than the current Jan to March Price Cap - rare for such a big name.

"Existing BG customers can get it too, and it's a massive saving compared to even the cheapest deals BG is offering direct (typically it's £130/yr cheaper than its cheapest).

"Plus, if you're already fixed with BG, it won't charge you early exit fees to switch to this (so see if it's cheaper - if it is, move.)"

British Gas has said it will pass on all the Government structural bill changes on its fixes on April 1.