British Gas, one of the UK’s Big Six utility companies, is rolling out a new service offering customers a twice yearly energy account check-up.

Tariff Check is available to the utility’s 10 million customers who have been with British Gas for more than one year.

The personalised six-month review is based on actual energy consumption and aims to communicate to the customer how they could save money by moving to a different British gas deal.

The utility also plans to promote insulation and energy-efficiency measures and its free online monitoring toolkit at the same time.

Ian Peters, managing director of Residential Energy at British Gas, said: “Tariff Check is the latest commitment from British Gas to make buying energy simple, transparent and fair for customers.”

The national roll-out of Tariff Check, which will appear on the customer’s bill, comes as pressure grows for a investigation by UK energy regulator Ofgem into profits made by the Big Six from selling gas to households.

Secretary of State for Energy, Ed Davey, called for an enquiry after suspecting energy companies of “overcharging their customers”.

British Gas-owner Centrica is set to reveal 2013 profits of £2.5bn this week. The British Gas household supply arm made a profit of nearly £600m last year, boosted by a 10.4 per cent rise in gas prices and an 8.4 per cent rise in electricity prices.