An estimated bill is your supplier's guess at how much energy you used, made when it has no recent meter reading. Guesses drift. The fix is to send a reading, or get your smart meter sending them, and ask for a corrected bill based on it.
This is general information, not legal or financial advice.
How do you know if your bill is estimated?
Your bill should tell you. Citizens Advice says to look for the word "estimated" or a letter "E" next to the meter readings.
If you have a smart meter and your bills are still estimated, the meter probably isn't sending readings to your supplier automatically. After a new installation or a switch of supplier, Citizens Advice says the account can take "a few weeks" to set up. So one estimated bill straight after a change isn't unusual. A run of them is worth chasing.
Why do estimated bills go wrong?
An estimate can't see what has changed in your home: a colder month, a new appliance, someone now working from home, or a heater left on. Citizens Advice warns that estimated bills can be too low or too high, and that the gap can grow over time.
- Too high: you pay for energy you didn't use, and your Direct Debit may be set higher than it needs to be.
- Too low: the bills look fine for months, then a real reading arrives and the catch-up bill is much bigger than you expected.
Neither is good for you. A bill that is too low is not a saving: it is a bill you will pay later, often in winter.
Why is my smart meter giving estimated bills?
Citizens Advice lists the common reasons:
- your supplier can't read your type of smart meter (for example, a first-generation meter after a switch or a move)
- the meter isn't connecting to the smart meter network
- the meter needs a new battery or has a fault
- smart mode has been turned off
- the meter isn't actually a smart meter
Ask your supplier whether smart mode is on and, if not, to turn it on. They may be able to do it remotely. If a newly installed meter never connects, Citizens Advice says the Data Communications Company has to connect you within 90 days, so tell your supplier if it has been longer. Don't try to fix a fault or change a battery yourself.
What does your supplier have to do about a faulty smart meter?
As of October 2026, Citizens Advice says that once you report a problem, your supplier has 5 working days to check whether the meter is working, try to find out why if it isn't, and offer to write to you with what it found. For each of those steps it doesn't finish in time, it must pay you £40. That should be paid within 10 working days, or another £40 is due for each unfinished step. The supplier should also give you a date to fix the problem, within 90 days of your request.
Ofgem extended these automatic £40 payments from February 2026, including when a supplier doesn't give a resolution plan within five working days of a fault report. In January 2026 it said it planned to cover meters that stay out of smart mode for more than 90 days later in 2026. Ofgem also said over 70% of homes in Britain have a smart or advanced meter, and more than 90% of those are working correctly.
How do you stop getting estimated bills?
- Send a reading every month. Citizens Advice recommends this to keep bills accurate. Use your supplier's app or website, or phone if you need to.
- Photograph your meters. A dated photo is your proof if a reading is ever disputed.
- Check it's your meter. Compare the MPRN (gas) and MPAN (electricity) on your bill with the numbers for your address. If they don't match, contact your supplier, because you may be billed for someone else's meter.
- Get help if you can't read the meter. If you are of State Pension age, disabled or have a long-term health condition, you can ask to join your supplier's Priority Services Register. Citizens Advice says this may include a regular meter-reading visit.
- Get your smart meter working using the steps above.
Not sure what MPAN, MPRN or "actual reading" mean? See our energy bill glossary.
What if a real reading shows you owe much more?
Citizens Advice says that when you send a reading for the first time in a while, your bill may be higher than the old estimates, because your supplier may have underestimated your use. You will usually need to pay it, but there are limits.
Your supplier usually can't charge you for energy you used more than a year ago, and Citizens Advice says your Direct Debit shouldn't be increased to cover energy used over 12 months earlier. Our guide to back-billing and the 12-month rule explains how this works.
If you can't pay the catch-up bill in one go, contact your supplier. Citizens Advice says "your supplier has to help you find a solution".
If the estimates were too high instead, you may have built up credit. See how to check your Direct Debit and get credit back.
What if your supplier won't correct the bill?
Complain to your supplier and explain why the bill is wrong. Citizens Advice suggests sending photos of your meter readings and keeping every message you send and receive.
Your supplier has 8 weeks to resolve the complaint. After that, or sooner if it sends you a "deadlock letter", you can take it to the Energy Ombudsman. The service is free. If you get a deadlock letter, you must escalate within 12 months of receiving it.
The Ombudsman can tell a supplier to take a practical step, such as applying a credit, and can make a small award for time and trouble. It says the most common award is around £50. For more on your rights, see your energy rights.
What to do next
- Check your latest bill for "estimated" or an "E" next to the readings.
- Take a dated photo of each meter and send the readings to your supplier today.
- Ask for a revised bill based on your reading.
- Set a monthly reminder to send readings, or ask your supplier to check your smart meter is in smart mode.
- Check the MPAN and MPRN on your bill match your meters.
- If your Direct Debit was set from high estimates, ask for it to be reviewed.
- If you can't read your meter, ask to join the Priority Services Register.
- Still wrong after 8 weeks? Take it to the Energy Ombudsman.
- Use the estimator to sense-check what a year of your energy should roughly cost.