In shared accommodation, it is a good idea to split the gas and electricity bills equally. It is cheaper to set up a direct debit to pay your bills.
It is sometimes easier to deal with the energy company if just one of the contract-holders is named on the utility contract. That person is responsible and liable to pay the whole bill until the end of the contract. The other contract-holders should pay their share to the contract-holder named on the bill.
If you’re the only person named on your energy contract, tell the supplier in writing that you’re acting on behalf of the other contract-holders and that you are all sharing the bills equally. This could help protect you in the event of a dispute.
Your energy supplier may allow you to set up an account that names all contract-holders on the contract.
You’re all liable to pay the bills until the contract ends if you are all named on the contract. This means that you are responsible for making sure the bills are covered completely, not just your share.
If a flatmate moves out, get a reading for that day and ask your supplier for for a bill so you can split the bill fairly.