Octopus backdating charges

1flatbattery

Today (19/08/25) I've just gone from being over £500 in credit last month to being landed with some mysterious back charges and a new bill of over £2500 in debit. This would take our energy bill to over  £5500 per year has anyone else experienced this and any suggestions how to deal with it? No significant changes in energy use and only small residential property. Any help welcomed

Brie

Are the bills based on estimated or actual readings?  If you have submitted readings but they haven't been applied then that is a complaint to be raised with Octopus.

Netexporter

1flatbattery said:

Today (19/08/25) I've just gone from being over £500 in credit last month to being landed with some mysterious back charges and a new bill of over £2500 in debit. This would take our energy bill to over  £5500 per year has anyone else experienced this and any suggestions how to deal with it? No significant changes in energy use and only small residential property. Any help welcomed

Do you submit regular meter reading, or have a smart meter to do it for you? If not, then you have been billed on estimated readings, which could be significantly adrift of your actual consumption.

Scot_39

Check your bills - the detailed calcs sections where it gives readins and then use then £ and pence - or your online portal / account - and see what it says about your billing and specifically the meter reading history.

Not with Octopus but others use terms for nature of measurements used like - smart (S) customer(C) actual(A) or estimated (E) are some of the possible variants.

Does the excess cover just on e fuel - or are you facing increased charges for gas and electric.

Are you on smart meter(s) or conventional or mix ?

If smart - still reporting as smart ? - and if not - when did it/they stop (you would imagine suppliers monitor and flag that - but it seems many do not catch failures - and simply revert to estimates ) ?

If conventional - when was the last time you submitted readings - contractually that might be required monthly for many of their tariffs - it is at my supplier for all customers in latest versions of T&Cs. 

Unless of course for age or health reasons you cannot read your meters. 

So are you able to read the meter - and if not - have you registered on their Priority Services scheme as unable - in which case they should be reading an old meter - or a failed comms smart one - ideally - every 12 months.

If the latest big bill is using estimated - how far from meter actuals today are they (and how many days apart is that from the big bill) ?

If your electricity meter has ever been dual rate - please provide all registers (peak off peak and total - as others at Octopus have fallen foul of issues there in ) - and gas if dual fuel home - and the dates - and correspnding date from that bills.

Again if estimated - and a long way out - have you provided an up to date set of measurements to have it redone / recalculated / issued etc ?

[And if a series of past bills were estimated - when was the last time actual readings were given / used (it wont change the amount necessarily - but will give an indication of how many months / years the correction - the c£3000 covers - and possibly suggest presence of savings on raw units needed for something called back billing protection that could reduce the demand - if Octopus havent already look at that and applied to properly - not all suppliers have in past).

£3000 may seem a lot - but seen posts relatively recently - where people had been underpaying for 2-3 years and amassing that sort of debt - one iirc was 4 years and spanned the whole of the crisis peak - and wracked up £1000s in underpayments.]

Ectophile

Have a good read of the Ofgem back billing rules, and see if it applies in your case https://www.ofgem.gov.uk/information-consumers/energy-advice-households/what-do-if-you-get-back-bill

QrizB

Ectophile said:

Have a good read of the Ofgem back billing rules, and see if it applies in your case

From what the OP has said:

1flatbattery said:

I've just gone from being over £500 in credit to over £2500 in debit. This would take our energy bill to over  £5500 per year

... it seems they've been paying £2500 a year, so the rebilling is roughly one year's payments. 
If this is the case, back billing is unlikely to reduce what they owe (Indeed it may have already been automatically applied by Kraken).