Your supplier uses regular meter readings, or smart-meter data, to work out how much energy you have used and applies your tariff’s rates and standing charges. It then sends a bill showing your usage, charges, payments and any credit or balance, usually monthly or quarterly. Check the details and contact the supplier promptly if the reading or bill appears wrong. Pay by your agreed method, and if you are struggling to pay, speak to the supplier as soon as possible because they may offer affordable repayment options or support schemes; check the latest guidance on GOV.UK and Ofgem.