Your gas and electricity are supplied under a contract or deemed contract from the supplier/s of your choice. ‘Dual fuel’ contract suppliers can supply both gas and electricity under contract.
In theory, contracts are reached by negotiation and agreement. In practice, most terms and conditions are presented to consumers on a ’take it or leave it’ basis within the framework of general licensing conditions imposed upon supply companies. The use of contracts means that finding out about your rights is now far more complicated than it used to be prior to privatisation of the energy industry.
You need to look particularly at the contract given to you by your supplier. There will be important differences in the terms of the contract when compared with those of other suppliers. Basic principles of contract law are governed by common law relying on definitions established in judicial decisions from the courts over many years. These operate within the wider framework of regulatory law.