British Gas Backbilling Dispute

linkbuster

Hello all.

Looking for a second opinion regarding a backbilling dispute with British Gas.

I was a British Gas customer from February 2024 until February 2025. My property was equipped with a smart meter and I paid monthly direct debit. However, I did not receive a bill until November 2025 for £1200, around half of which was consumed more than 12 months prior. I raised a complaint with British Gas, but for 4 months they insisted that my account was not applicable for backbilling due to various nonsensical reasons. In this period my details were also passed to a debt recovery agency and adverse credit markers were placed on my credit reports.

It was not until I approached the ombudsman in February this year that British Gas conceded that the account should have in fact have been issued with a backbilling credit. They issued a new invoice in March including a backbilling credit relating to energy consumed prior to November 2024. However, I believe that as I was yet to receive an accurate invoice, the backbilling window should have moved in the following 4 months to the date of issue of the revised invoice, effectively voiding the remaining charges. Having read Ofgem's guidance and standard licence conditions, I was under the understanding that they can only recover charges more than 12 months old if they have already issued an accurate invoice. However, the ombudsman has sided with British Gas on this issue and has stated that the 12 month window anchors to the original "charge recovery action" in November, despite this not being an accurate reflection of my liability at the time. My understanding of the license conditions is that the 12 month window has to anchor the the first compliant and accurate invoice.

Are the ombudsman correct? Despite requests, their responses make no reference to any relevant license conditions on which I can understand their decision.

Have they got it right? I have exhausted the ombudsman process but wanted to understand the liklihood of success in making a legal claim, or whether I should just suck up the remainder of the invoice.

Thanks

MattMattMattUK

Was this an ombudsman (person/job role) decision or an adjudicator (the first line people at the Ombudsman) and was the decision then escalated to an ombudsman at the second complaint (a final decision from the Ombudsman organisation)

From what you have said yes, they have got it right, but it is hard to tell without a lot more detail. Back billing is more complicated than most people realise. They cannot charge you for energy they bill over more than a year ago, but they can use account credit to cover that. They can also correct a bill, if it is not accurate the first time, which further complicates the billing and recovery situation, it is not a blanket get out of paying for energy over a year previous that was not billed, or was billed with some errors. At the point they bulled you in November 2025 they could bill you for the whole lot, but they could not request additional funds to cover that period, however they could use all they credit on the account to cover Feb 24 to Nov 24, then require more funds to cover the Dec 24 to Feb 25 period.

There is also some slightly woolly language in your post, you said you did not receive a bill, but if one was available in your BG account then that further complicates things.

You would need to supply us with energy uses by month, credit paid in via Direct Debit per month, when bills were issued (regardless of if you received them or not), what periods they were for etc. for us to be able to work out what applies.

MWT

https://forums.moneysavingexpert.com/discussion/6670893/british-gas-backbilling-dispute

Yes, they have got it right, the November '25 bill correctly charged you for electricity from November '24 onwards so that pegs their ability to bill you for that period even if there were subsequent changes to that bill.

Potentially they were even right to bill you for the period from Feb '25 due to the DD payments you had been making, so I'd take the win on that one and move on.

HillStreetBlues

Apart from the back billing issue, did you get the compensation for BG not billing within 6 weeks of leaving?

WiserMiser

Not sure whether the badly rated BG allow it for new customers, but this highlights another advantage of paying by Monthly Variable Direct Debit: you don't build up any credit or debit !🙂

Of course, this means bigger bills in winter and smaller ones in summer, but it also gives you a much better indication of how much energy you’re using and how much it's costing.

linkbuster

Thanks for the replies. A few points of clarification.

I was a British Gas customer from 22 February 2024 to 27 February 2025 and paid monthly direct debits of £98.50 throughout. No bill was issued during my time with BG and no earlier bill appears on my online account.

The first bill arrived on 10 November 2025, around nine months after I had left. It sought approximately £1,200 and included consumption dating back to July 2024. The bill also showed a "previous balance" of -£471.01 despite there being no earlier bill, and only credited some of the direct debit payments I had made during the course of the tariff. I assume the remainder were allocated to the un-issued bill covering the earlier part of the supply period.

I complained immediately. After four months of dispute, referral to debt collection, and adverse credit markers being recorded, BG eventually accepted that backbilling should have been applied. Following my referral to the Energy Ombudsman, they issued a revised bill on 18 March 2026 which included backbilling credits of £574.09, reducing the balance payable to £606.75. They also applied the late billing credit.

The Ombudsman also awarded me £200 compensation for poor service but concluded that the remaining balance remained payable.

My first disagreement was with the Ombudsman's view that the 12-month backbilling window is fixed by the original November 2025 bill. My reading of SLC 21BA.2 is that the supplier must have already taken a compliant charge recovery action before relying on the exception to the backbilling rules. As the November bill was later accepted to be non-compliant and had to be corrected, I question whether it can still anchor the 12-month period. Ofgem's consumer guidance also appears to emphasise that previous billing must have been accurate for charges older than 12 months can be recovered. That said, I'm not a subject matter expert so am happy to concede that my interpretation could likely be wrong.

My secondary concern is transparency. BG provided only summary figures for the backbilling calculation and, despite several attempts to reconstruct it, I have been unable to reconcile the figures against the tariff, consumption and standing charges. The Ombudsman says it has validated the calculation but has not explained how. I don't understand how they could have as one invoice remains entirely missing and the case file submitted by BG does not contain any usage data. The Ombudsman is no longer responding to requests for clarification.

Based on the above, do people still think the Ombudsman has interpreted the backbilling rules correctly? The consensus so far appears to be that they have, but I would be interested in any views on the points above.

MWT

https://forums.moneysavingexpert.com/discussion/comment/82024080#Comment_82024080

Ignore the amount of money they were seeking and the payments you had made for the moment, did the November bill seek to charge you for the correct amount of energy used up to 27/2/25 ?

If so then that is what has anchored the back-billing date. The bill can be wrong in the way it applied credits or payments made and still anchor the date as subsequent bill revisions are not adding to the amount of energy they are attempting to bill…

linkbuster

https://forums.moneysavingexpert.com/discussion/comment/82024112#Comment_82024112

The energy actually stated and itemised in the November bill does appear to be correct. However, this bill also carried forward a balance of -£471 for which I have never received a bill and for which no usage data or meter reads exists on my online account.

MWT

https://forums.moneysavingexpert.com/discussion/comment/82024163#Comment_82024163

Then you have been billed for the energy as at that date and that does nail the point where back-billing can be taken from.

There may be other things wrong with the bill they issued but that doesn't help you from a back-billing perspective.

linkbuster

https://forums.moneysavingexpert.com/discussion/comment/82024294#Comment_82024294

So the accuracy requirement relates to energy consumed rather than liability. Got it. Appreciate the clarification.

In terms of calculating my actual liability, I have paid a total of £1230 via monthly direct debit over the course of the tariff. I have been accurately billed (meaning energy usage is accurately stated on an invoice) for only £1311 usage in total, meaning there would have only been a delta of £81 to be paid. The November invoice indicated a remaining balance to be paid of £1209, and the March invoice subsequent to the application of backbilling credits indicated a remaining balance of £606. I am at a loss as to how BG have come to these figures (or how the Ombudsman has agreed with them).

MWT

https://forums.moneysavingexpert.com/discussion/comment/82024438#Comment_82024438

Had you even been with BG before the start of this period in Feb '24?

For what its worth, based on how the Ombudsman has ruled in the past I'd say you owed the £81 and that would be it.

… but it is harder to explain where the result you have ended up with has come from, if it is as simple as you being with them for 12 months only then you take the opening meter reading from the closing meter reading and pay for the use at the tariff rate applicable at the time.

I wouldn't give up at this point if the story is just as I outlined as there is no scope in there for older balances to come into play…