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Over one million energy customers due refunds

An investigation by Ofgem has found that over one million energy customers were overcharged £7.2million between 2013-2020, after switching suppliers or tariffs. Some overpaid hundreds of pounds because energy firms failed to stick to rules meant to protect customers' prices.
The 18 suppliers involved are now paying £10.4million to affected customers.
You might be affected if you are or were a customer one of the 18 firms during this time period and:
- you were on a standard variable tariff and switched to another supplier
- you were on a fixed term tariff and switched to another supplier
- you were on a fixed-term tariff and moved to another tariff with your existing supplier.
Some energy firms have already paid their customers back and others are in the process of doing so.
Keep reading to find out if you could be owed a refund. Or use Which? Switch to compare gas and electricity pricesand find a supplier whose prices and service are right for you.
Energy firms that overcharged customers
Some customers of all of the biggest six energy firms are affected. Five firms overcharged more than 100,000 customers.
The table below shows how many customers of each supplier overpaid.
Energy firm | Number of affected customers |
Bristol Energy | 12,617 |
British Gas | 141,415 |
E | 20,970 |
Eon | 28,126 |
EDF Energy | 79,083 |
Engie | 9,061 |
ESB Energy | 1,961 |
Some customers of Green Network Energy were also overcharged. Green Network Energy stopped trading recently and customers are being moved across to EDF Energy. Ofgem told us that it is talking to EDF Energy and Green Network Energy's administrator and will give an update shortly.
Affected customers: what you need to know
All 18 energy suppliers have agreed to refund all affected customers. Some are also making extra 'goodwill' payments.
If you are affected, your energy supplier should contact you and arrange to pay you back. This includes your old supplier, if you switched away.
Eon and Npower have already paid back their customers in full. The rest are still making payments and have six months to do so.
If your supplier stopped trading or was bought by another supplier, Ofgem says it is talking to the new suppliers, administrators and suppliers of last resort to arrange refunds.
Where firms repeatedly didn't stick to the rules, or there was other 'serious conduct', Ofgem said it worked with suppliers to get more redress for customers.
Ofgem says it will make sure that all the money owed to customers is paid in full.
Find out what to do if you're struggling to pay your energy bill.
What to do if you think you're owed money by your energy supplier
Your current or previous energy firm should contact you if you paid too much.
But if you think you were overcharged when you switched supplier or tariff and haven't heard from the energy company, contact it.
Ask if to confirm whether you are affected and due a refund. You can use our letter to complain if your energy firm overcharges you.
Why were energy customers overcharged?
When you switch energy firm or move to a different energy deal with your existing supplier, the price of your existing tariff should stay the same until the switch is completed.
But this didn't happen in the case of one million customers between 2013-2020, Ofgem discovered.
This was usually because suppliers didn't have 'adequate arrangements in place to make sure the protections were applied in full when customers decided to switch', it said.
Several suppliers told Ofgem about the problem. It then asked all suppliers to check and found that 18 were affected.
Ofgem warned that it will open enforcement cases if suppliers repeatedly break switching rules in future.
Know your rights: how to complain about your electricity and gas bills.