The Money Saving Expert founder often shares his advice on X, and in a post he told billpayers: “Energy firms AREN’T allowed to back-bill over 1 year. If you’re sent a bill for the first time about energy from past years (providing you didn’t obstruct em in getting the info) it’s usually wrong.
“You needn’t pay it. Make a formal complaint and if needed go to Energy Ombudsman.”
He added: “I’m giving evidence in parliament on this soon. If it’s happened to you let me know (and let me know what happened).”
Energy bill back billing rules
If your gas or electricity supplier believes you have not been accurately billed for energy you’ve used, they may send you a back bill.
These bills are sometimes called ‘catch up’ bills, and are intended to cover a period where you’ve used energy but have not been charged for it.
If you get one of these from your supplier, check whether you’re protected by Ofgem’s back billing rules before deciding what to do next.
Energy firms AREN’T allowed to back-bill over 1 year
Ie. if you’re sent a bill for the first time about energy from past years (providing you didn’t obstruct em in getting the info) it’s usually wrong. You needn’t pay it. Make a formal complaint & if needed go to Energy… pic.twitter.com/PNhKKsVyQ5
— Martin Lewis (@MartinSLewis) March 3, 2025
Ofgem back billing rules
You cannot be charged for energy used more than 12 months ago if:
- you have not had an accurate bill for it before, even though you asked for one
- you have not been informed about any charges due via a statement of account before
- your Direct Debit amount was previously set too low to cover any charges due
Suppliers must make these rules clear in their contract terms and conditions.
The rules only apply to domestic energy consumers and microbusinesses.
What to do if you get a back bill from your energy supplier
Contact your supplier and let them know. They should refund any money taken in error, which could be all or part of the bill.
You’ll find your supplier’s contact details on their website, or on your energy bills.
If you want to write to them or send them an email, you can use the Citizens Advice back billing example letter.
You can complain about your energy supplier if they continue to ask for payment for a period covered by Ofgem’s back billing rules.
The rules do not apply if you have acted unreasonably by:
- stopping your supplier from billing you accurately, for example by blocking access to your meter
- ignoring requests for payment from your supplier
- stealing electricity or gas
Paying a back bill
You are responsible for paying for the energy you have used in any period not covered by the back billing rules.
If you’re worried about being able to pay, take a look at the help and support options available if you cannot afford your energy bills.
How to help make sure your energy bills are accurate
The best way to avoid getting a back bill is to make sure you receive regular, accurate bills from your supplier.
Make sure the bills you get accurately reflect the energy you’ve used. If you think there’s something wrong with your bill, for example if you’ve been undercharged, contact your supplier right away.
You should also contact your supplier to let them know if you do not receive a bill for energy you’ve used.
If you do not have a smart meter, make sure to give your supplier regular meter readings.
