Centrica chief executive Sam Laidlaw told ITV News Business Editor Laura Kuenssberg that he agreed with David Cameron that "there has been too much confusion and proliferation of different tariff types."
He said simplifying pricing would mean that "the range between cheapest and most expensive is going to narrow" and that "the deeply discounted deals are disappearing".
British Gas was writing to customers every six months to advise on the cheapest tariffs available, he added.
More top news
Thunderstorms affect mostly southeast England tomorrow with a mixture of sunny spells and showers into the afternoon.
The government has been forced to release a full report into the impact of fracking, after initially handing over a heavily-redacted version
Midfielder Kartie Chapman's husband and three sons, will be nervously watching the semi-final against Japan back in England.