Fixed-rate energy tariffs ending, warns Gocompare.com

If you're on a fixed energy tariff, it's time to check your deal or face being caught out by a huge jump in the price of heating and lighting your home.

Households could face energy price rises of up to £312.51 as 24 dual-fuel tariffs come to an end at the end of this month, reckons the comparison site Gocompare.com.

British Gas, Co-operative Energy, Extra Energy, First Utility, iSupply, M&S Energy and Scottish Power all have deals expiring on Wednesday 30 September, at which point customers who do nothing will be rolled onto their supplier's more expensive standard variable tariff.

Worst hit could be First Utility customers in the Norweb area on the expiring iSave Fixed September 2015 v27 tariff . They could face an increase of a staggering £312.51 if they allow themselves to be automatically switched on to the supplier's iSave Everyday standard tariff, instead of switching to a better deal.

"Households who are loyal to their energy provider once their current deal expires are usually rewarded with a significantly more expensive tariff that doesn't represent value for money," warned Caroline Lloyd of Gocompare.