When you change your tariff, we use your personal projection to calculate your monthly Direct Debit amount. The personal projection assumes that you’ll use the same amount of energy as last year, and doesn’t include any future or current debit or credit balance on your account.

When you sign up to a new tariff, the Direct Debit doesn't change straight away. That’s because the personal projection on your new tariff is an estimate. 

Every 3 to 12 months we review your payments, making sure it’s aligned with your usage. To do this we use your monthly meter readings, weather data and information held about your previous household usage.

If we see that your usage is higher or lower than expected, we’ll adjust your monthly payment amount to reflect this. 

To see how much you can change your monthly Direct Debit by, you'll need to log into your online account and use our Direct Debit calculator.