While many customers may see a reduction in their gas and electricity bills as a result of recent price cuts, millions of homes could miss out as they are locked into long-term fixed-rate tariffs.
This is according to This is Money, which noted British Gas alone has 1.3 million users on these deals who will not be able to benefit from the result price cuts unless they pay a penalty to end their contract early.
However, managing director of energy at the firm Ian Peters said many consumers have chosen long-term deals to guard against future price increases.
"It is in the balance of probability that wider prices will go up before 2014," he said.
Recent research by energyhelpline.com found there are high and low cost fixed tariffs. Individuals who fixed their tariffs last year through a price comparison service are still likely to be better off as they are more likely to have selected a low cost tariff.
Make sure you're not paying too much for your energy - compare gas and electricity prices now at energyhelpline.com or call 0800 074 0745