A day with very little energy use can still add a charge to the bill. In Great Britain’s energy market, a standing charge is a daily amount separate from the price charged for each unit consumed.
Ofgem explains the distinction between unit rates and standing charges. The amounts and tariff arrangements vary, so use the rates on your own agreement rather than an old screenshot or somebody else’s bill.
Split a sample bill into two calculations
For a purely illustrative example, suppose a tariff has a standing charge of 0.50 currency units a day. Over 30 days, that component is 15.00 before considering anything else. If consumption is 100 units at an illustrative 0.25 each, the usage component is 25.00.
Those invented figures demonstrate the arithmetic only. They are not current tariff rates, and a real bill may include taxes, adjustments, credits or separate charges for more than one supply.
When comparing two bills, check the number of days first. A longer billing period can have a larger standing-charge total even when the daily rate is unchanged. Then compare the usage and unit rate separately.
Read the tariff before deciding what a saving means
A lower unit rate does not automatically make a tariff cheaper for every household. A different standing charge can change the overall comparison, especially when annual use is low. Estimate the whole cost using your actual consumption pattern and the applicable terms.
If a property will be empty, ask the supplier what charges continue and what options apply. Do not assume that switching appliances off ends the supply agreement or removes its daily charge.
Keep a note of the tariff name, rate dates, billing days and meter-reading basis. That creates a useful starting point for a supplier query without mixing up the cost of remaining connected with the cost of the energy actually used.