What this guide covers
This guide explains charges that commonly appear on UK energy bills and catch people by surprise. It is educational information to help you understand your bill.
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The charges most households do not fully understand
Most UK energy bills contain more than just a unit rate and a standing charge. Several other charges, conditions, and billing practices can result in households paying more than they expect. Understanding them does not require specialist knowledge, but knowing they exist is the first step to managing them.
This guide covers the most commonly misunderstood and overlooked charges on domestic energy bills.
Standing charges: paying before you use anything
The standing charge is a fixed daily amount added to your bill regardless of how much energy you use. For a typical dual fuel household paying by direct debit, standing charges from July 2026 amount to approximately £315 per year before a single unit of energy is consumed.
Many households focus on unit rates when comparing tariffs and overlook the standing charge entirely. On an annual basis, standing charges can represent a significant portion of a bill, particularly for lower-usage households.
When comparing tariffs, always check both the unit rate and the standing charge. A tariff with a lower unit rate but a higher standing charge may cost more overall for your usage level.
Exit fees: the cost of leaving early
Most fixed energy tariffs include an exit fee that applies if you leave before the contract end date. Exit fees are charged per fuel, so a dual fuel account typically incurs two exit fees if you switch early.
Common exit fee levels in the current UK market range from zero to £75 per fuel. On a dual fuel account with a £75 per fuel exit fee, leaving early costs £150.
Most suppliers waive exit fees within a window of typically 42 to 49 days before a fixed deal ends. This allows you to arrange a new deal and time your switch to coincide with the contract end without paying a penalty.
Deemed rates: what you pay when you move in
When you move into a property and have not yet contacted the existing supplier or chosen a new one, you are automatically placed on a deemed contract. Deemed contracts are treated as standard variable tariffs and are subject to the Ofgem price cap.
During the brief period before you set up a formal account, the rates applied may be slightly higher than the standard variable tariff. Deemed contract rates are regulated by Ofgem but have historically been at the top of the permitted range.
The practical implication is to contact the existing supplier as soon as you move into a property to establish a formal account, and compare tariffs promptly.
VAT and direct debit overpayments
All domestic energy bills include VAT at 5%. This applies to both unit charges and standing charges. Most tariff comparison tools display prices inclusive of VAT, but it is worth confirming when comparing.
If your monthly direct debit is set higher than your actual energy consumption costs, credit accumulates in your account. Ofgem data shows UK households collectively held £3.17 billion in energy account credit on average across 2025, with an average household credit balance of £199.
Suppliers are required under Ofgem rules to refund credit balances promptly on request. If your account is consistently in credit, ask your supplier to reduce your monthly direct debit to better reflect usage.
Estimated billing: when the bill does not reflect reality
If you do not have a smart meter and have not submitted a meter reading, your supplier produces estimated bills based on historical usage patterns. Estimated bills can be higher or lower than your actual consumption.
If the estimate is too high, you overpay and build up credit. If it is too low, debt accumulates on your account and a larger corrected bill arrives later.
Submitting regular meter readings, or having a smart meter installed, prevents estimated billing and keeps your account more accurate.
What to check on your next bill
When you receive your next energy bill, check five points:
- Do the unit rates and standing charges match your agreed tariff or current cap rates?
- Is the bill based on actual or estimated readings?
- Is your account balance in credit or debit, and does it look proportionate?
- Is your direct debit amount proportionate to your annual bill?
- If you are on a fixed deal, what is the exit fee and contract end date?