Some electricity and gas suppliers offer special dual fuel plans, offering incentives and reduced prices for combined electricity and gas services. Dual fuel is when the same energy supplier bills you for both gas and electricity under the name of one tariff. Suppliers offer incentives to customers who choose their dual fuel plans in the form of discounts or reduced prices. Another advantage of being on a dual fuel plan is that you only have one company to contact with any enquiries relating to your supply or billing.