On a fixed tariff, your unit rates and standing charge won't change for the duration of your contract
Your unit rate is the amount you pay for each unit of energy you use (measured in kilowatt hours)
Your standing charge is a daily rate, which pays for actually getting the energy from the generators all along the wires and into your home
Your monthly Direct Debit amount isn't fixed. It's our best guess at the amount you should be paying to cover your energy charges, based on how much energy we reckon you'll use. If you're using more or less energy than we thought, and you start building up too much credit or debt, you can edit your Direct Debit from your online account. We'll check in every so often, too, to make sure your monthly payment is about right to cover the cost of the energy you're using.
At the end of your fixed tariff we'll give reasonable notice of your options. If you don't let us know your preference, we'll move you onto a flexible tariff.