Historical bills changing without explanation?

This may be an old thread, but still relevant. Just like to OP, I have downloaded bills, only to then later log in again to find the bills for the same periods have all changed in value.

In my case, after the initial downloads, I submitted a meter reading. It seems all the bills have subsequently been ‘adjusted’ to new values. If I hadn’t download previous versions, it would be nigh impossible to be any the wiser.

Now adjusting the bill for a new meter reading may be expected …. but EVERY BILL going back TWO YEARS has been adjusted. Today it is July 2025 - all bills going back to period ending June 2023 has been adjusted/amended. Of course over those two years I have left other meter readings and made payments.

Is it even legal to adjust bills that far back ? How can OVO re-assess bills despite having had meter readings in the mean time, and payments made ? Shouldn’t a payment ‘close off’ earlier periods, so no adjustments can be backdated beyond ?

I run a business - when I receive a bill (invoice) it is for a fixed amount - it doesn’t just decide to later adjust itself to a different value, let alone go back years past. OVO’s bills are actually some weird hybrid of an invoice and a statement - which should be, and are, for most businesses two separate documents - and is not really a bill, as it just lumps sums the previous period on it as a running total ; and the months before that ; and the month before that ; & etc.  This is a terrible way to charge people. Have an invoice for the period in question. And a separate statement showing the running total, like every other real company I’ve ever dealt with. Not merge them together obscuring when adjustments have been made to past bills. TWO YEARS of amended bills !!

And this isn’t the first time its happened with OVO either. I actually dread leaving a meter reading, because I know all the bills going back God knows how long will magically have new values, including ones that have had meter readings previously submitted (effectively therefore overwriting those readings ; what is the point of submitting if it later is just scrubbed ?).

Morning ​@Yeti and welcome to the OVO Forum.

I’m sorry to hear of what’s happened here - I can fully understand how frustrating this would be, especially if you’re running your own business. 

Do you have previous copies of the older bills which prove that they’ve been recalculated? It sounds as if maybe a reading wasn’t submitted for a very long time, which would mean that you’d been billed to estimates which were out of line to your usage - I’m not sure whether this is the case? If a read is submitted and it’s out of line with our estimates then we would recalculate previous estimates so that everything falls in line. This can mean that your statements will be readjusted. 

On the Forum we don’t have direct access to customer’s accounts. My recommendation here is to make a complaint. The Advisor that picks it up will then need to log a complaint and give you a complaints reference number, and will contact you with a view to getting this resolved, and explaining what has happened. By all means keep us updated on the Forum as to how you get on - I hope this is resolved quickly for you.

My brother has had issues with OVO in 2024 saying he owed thousands. During a phone call back then he was told it was because he hadn’t sent any readings in and it was all estimated, he gave up to date readings and they cancelled debt and refunded him over £2000. A month or so later he got another email saying they had got it wrong he should never have had a refund and he had to pay it back. He has been doing this since 2024. 

2025 he had a new meter installed and has a IHD which is supposedly sending real-time readings to OVO. Also last year he had Solar, battery and air source heat pump fitted to his housing association home. 
He has just received a email saying since Aug 2023 to 2025 he has been undercharged instead of £4977.67 which he’s paid he should have been charged £6572.84. 
it says we undercharged you but you don’t have to pay this ? But then says he is actually in debt £602.16 and has to pay this.

after a phone call this morning they said he’d been underpaying for a yr, how he has a smart meter?

10 minutes after putting the phone down he has an email saying he’s in debt £2212 ! 
what is going on, who should he be speaking to he’s really had enough of it !

Hey ​@Tricko,

Thanks for reaching out. Since we’re a public-facing customer forum, we don’t have access to individual accounts, which means we can’t see all the details of your situation. It looks like there was an issue with the previous readings not being supplied, which led to some incorrect estimated charges when the new meter was installed. The result is that it appears your account has been rebilled based on new information, and the email you shared explains what you owe and what you don’t.

For the best help, I recommend continuing the conversation with our Support Team. They can look at your account and provide you with tailored help. Unfortunately, we can’t dive into specifics here due to the open nature of the forum, but I’m sure the Support Team will take great care of you!

If you are unhappy with the recalculation, you have the option to file a complaint. One of our complaints handlers will investigate the circumstances surrounding your issues and work with you to find a resolution. If you are not satisfied with the resolution provided, you can escalate the complaint to the ombudsman. All relevant information will be forwarded to them for further investigation and to reach a final decision.

If you need to raise a complaint, you can find out more about our complaints procedure on the website: https://www.ovoenergy.com/feedback.

Thanks for your help. I will tell my brother to file a complaint. He’s in a small two bed property with his young son and we cannot work out how he is being billed this much. We pay far less than him in a three bed with two big teens, showering all the time!