Two kinds of reading
Every energy bill needs a number for how much was used. An actual reading is a real figure taken from the meter, either by a person, by a customer who reports it, or automatically by the meter itself. An estimated reading is a calculated figure used when no real one is available. Bills are allowed to rely on estimates in many places, but they are usually supposed to be labeled as such, often with a letter or a note next to the reading.
Neither type is automatically wrong. An estimate can be close to the truth, particularly for a household with steady habits. The problem is that it can drift, and when it does, the bill may be too high or too low until a real reading corrects it.
Why estimates happen
There are several common reasons a supplier may estimate rather than read:
- Access problems. The meter is indoors, in a locked room, behind a gate, or under snow, and the reader could not reach it.
- Reading schedules. Some utilities send a reader only a few times per year and estimate the months in between.
- No customer reading supplied. Where households are asked to report their own readings, no report means an estimate.
- Older meters. Basic meters need a person to look at them. Meters that report automatically reduce the need to estimate, as discussed in the explainer on smart meters and the smart grid.
- Communication faults. Even automatic meters can lose their connection or fail to send data for a period.
- Recent changes. A move-in, a switch of supplier or a new account may start with an estimated opening figure.
How estimates are usually calculated
Methods differ, but most estimates draw on your past use. A supplier might look at what you used over the same period last year, or at the average daily use between your last two real readings, then project that forward. Some also adjust for season or typical household size. If you have only just moved in, there may be little history, so the estimate may rely on averages for similar homes.
This is why estimates can miss badly after a change. A household that adds electric vehicles or heat pumps, or starts working from home, or that goes away for a long vacation, can use very different amounts from the pattern the estimate assumes.
What can go wrong
If estimates run low, you pay less now but may face a larger bill later when a real reading catches up. That catch-up can arrive as one big charge, which is a poor surprise for a household budget. If estimates run high, you are effectively lending the supplier money until a correction is made. In many places, a credit then goes onto your account or is refunded, but the process and timing vary.
There can also be knock-on effects. If you are on a plan where the rate changes at a certain date, an estimated reading can put some use on the wrong side of the date. On time-based plans, an estimated total cannot reflect when you actually used energy.
How to check your own meter
You can usually read the meter yourself. The basics are the same everywhere, though meter designs differ:
- Find the meter. It is typically near where the supply enters the home, in a basement, garage, utility room or on an outside wall.
- Identify the type. Some have a row of digits, some have dials, and some have a screen that cycles through values.
- Write down the whole number of units shown, in the order displayed. Ignore any decimal portion unless your supplier asks for it. For dial meters, note the lower number when a pointer sits between two digits, and check your supplier’s guidance for the details.
- Take a photo with the date if you can. A photo is a handy record if there is a dispute later.
- Compare it with the reading on your bill. If yours is higher or lower than expected, an estimate is a likely reason.
Never open a meter or tamper with it. If there is a seal, a damaged case or a fault, contact the utility and let authorized staff deal with it. Electrical and gas equipment can be dangerous.
Submitting a reading
Most suppliers accept customer readings by website, phone, mobile app or a form. Some set a window each billing period when readings are accepted. Submitting a reading shortly before the bill is generated gives the best chance that it will be used. Give the date you took it, and keep a copy of what you sent. If the unit on the meter is not the same as the unit on your bill, ask how to convert, or check the supplier’s guidance.
A regular habit helps. Taking a reading on the same day each month, for example, builds a record that makes it easy to see changes in use and to spot problems early. It also pairs well with learning how kilowatt-hours charged work, since you can then see how the numbers you wrote down turn into money.
When your bill seems too high
If a bill looks off, check whether the reading is marked as estimated. If so, compare it with your own reading and send in the real figure. Ask the supplier to reissue the bill based on the actual figure. If a large estimated debt has built up, ask for a payment arrangement. Many regions have rules limiting how far back a supplier can bill for past usage, and your energy regulator’s site may explain those rules for your area. Rules differ widely, so check locally.
This is general information, not advice for a specific dispute. Your supplier, local regulator or consumer body can explain the rules that apply to you.