A Direct Debit is a payment plan

A monthly payment is usually set against expected annual usage, prices and the account balance. It is not a measurement of the energy used in one month and it is not automatically the same as a bill total.

Illustrative example: identify the change

If a payment changes from £120 to £200 a month, the increase is £80 a month. That is a change in the payment request, not evidence that the household used £80 more energy or that the bill charge rose by £80. Keep the previous payment, current payment and derived difference as separate facts.

Ask how the new amount was calculated

Write down the old payment, new payment and date of change. Ask the supplier to show the usage, rates, balance and payment period used in its calculation, and check the readings against your bills.

  • Keep the supplier explanation with the statement that triggered the change.
  • Check whether an earlier debit or credit is included.
  • If the explanation depends on estimated usage, submit a dated reading where safe and practical.

Check the balance and future charges

A credit balance may be needed for future usage, while a debit balance may reflect earlier charges. Look at the billed-through date and upcoming payments before deciding what the balance means.

If the bill is not available

You can still ask the supplier to explain the new payment. Ask for the account balance used, predicted annual usage, tariff assumptions, payment history and any shortfall being recovered. When the statement becomes available, compare the explanation with the readings and dates rather than guessing the missing figures.

  • A Citizens Advice page linked in the sources is England-specific; use the relevant nation-specific guidance elsewhere in Great Britain.
  • Do not turn an unavailable bill into a zero balance or an estimated kWh figure.
  • If the supplier will not explain the calculation, keep a dated record and use the complaint route.

Use a calculator as a transparent sense check

The energy bill calculator can separate usage charges and standing charges for a chosen period using your own figures. It cannot reproduce supplier forecasting or decide what payment a supplier should set.

A concise question for the supplier

You can ask: “Please explain how you calculated my new monthly Direct Debit. Please show the expected annual usage, unit rates, standing charges, current account balance, payments already made and any amount being recovered from earlier charges.” Adapt the wording to the information you actually have and use the supplier’s secure channel.