Estimated Annual Consumption (EAC) - DIY tutorial series

  • 23 September 2020
  • 4 replies
Estimated Annual Consumption (EAC) - DIY tutorial series
Userlevel 7

Updated 26/01/2021

Estimated Annual Consumption - your guide


What is an EAC?


EAC stands for Estimated Annual Consumption. We (and the rest of the industry) are able to use this figure to forecast the energy usage at a property over the next 12 months.


What is an EAC based on?


The EAC is calculated using the metering system’s historical consumption. Where there are regular meter readings, the EAC will be based on the previous year. EACs are re-calculated each time a reading is validated by our Data Collector.


How do we use an EAC?

  • Sometimes to Calculate your Direct Debit (see ‘Usage projection’ for more info)
  • Estimating readings when we have no 'actual' readings
  • Estimating consumption when a meter is faulty

We don't always use EAC to predict a member's usage - as stated below, EAC is only used for supplies where you don’t have a smart meter and there's no actual readings in the past 12 months.


What is Usage projection?


Usage projection is a figure produced by our billing system, that uses smart meter readings (if available) to project the usage for you over the next year. If you don't have a smart meter, it uses any actual meter readings obtained over the past 12 months.


If we don't have any actual meter readings within the last 12 months, we'll use your EAC and AQ (the gas equivalent of EAC) to calculate your usage projection.


Usage projections will be displayed on monthly bills and will also be used for Direct Debit check in’s and renewal quotes.


How do we update an EAC?


Whenever a new reading is submitted to industry, a new EAC is calculated and sent to us to use.


If your EAC is incorrect, you should keep sending us regular readings. As the EAC is calculated based on the entire reading history of an electricity supply (MPAN), submitting regular readings over a period of time will gradually change the EAC until it matches the member's usage. The better alternative is to get a smart meter!


There are some exceptions where we may amend the EAC in other ways (e.g. when there has been a sudden and large increase/decrease in the EAC that doesn't match the most recent readings) but these wouldn't be applied without supporting readings.


We can't contact the industry to say we want the EAC amended, so all we can do is ensure the readings are correct on an account. If you’re not sure about your latest DD check in, the best thing to do is ensure we have accurate meter readings, and book a smart meter exchange. 


What is the average EAC?


The current average EAC / AQ, as specified by Ofgem, is as follows:

  • Electricity (P1): 3,100 kWh
  • Electricity (P2): 4,200 kWh
  • Gas: 12,000 kWh


What have we missed? Comment below. 

4 replies

Userlevel 5
Badge +1

On this subject.

My experience with my previous energy supplier, hence the move to Ovo.

I have an unusual situation if the fact that I have 3 supply meters, 2 gas & 1 electric, 

The normal computer driven usage forecast (EAC) puts a higher usage figure over the winter months as demand increases, especially when you incorporate heating systems.

In my case, my extra gas meter has zero usage over the winter & a high usage over the summer.

 At every bi annual account review, the generated forecast model was the complete opposite the known service supply data.

So twice a year, a phone call to the cs department resulted in the high swing of my DD payments being manually adjusted back to the original payment amount.

That was until  the beginning of 2020, when my request to have my projected usage & costs looked at again resulted in the response of NO,  the option of the cs team to manually override the computer generated assessment had been revoked, at management level the request to manually readjust my account was also denied as they hadn’t got the authority to do so.

The only advise offered was to raise an official complaint & I did just that.

 Eventually it was all resolved in my favour, but enough was enough hence the move to Ovo.

​​​@Tim_OVO  A nice insight, I’m sure my 3 meters & slightly odd usage & setup will give EAC a good workout :grinning:


Userlevel 7

And hopefully this will be better with 2 of your 3 meters as they are smart meters. Allowing a) a better EAC and AQ, and b) an alternative to the EAC and AQ when possible. 


Although in your case, @TomThumb we’re still working on getting your smart meters ‘smart’. For anyone else interested, see this topic for more info...

Hi. Basically, last year OVO misread out meter, getting the digits mixed up and suggesting we had hence used a vast amount of electricity. I contacted them, and corrected the reading, which they accepted was clearly an error on their part. Nonetheless this summer I received an email suggesting we were again using huge amounts of electricity. I explained again that it was their previous mistake , but they nontheless increased the monthly bill from £140 to nearly £600. 

I entered our correct reading online but have heard nothing. I have complained. Nothing. They have now taken over £2000 from my account. 

I'm going to the ombudsman and switching provider, but should I involve the police for what is effectively theft??

I can get nowhere with OVO who have been frankly appalling. 



Userlevel 7
Badge +4

Good morning @Flatty ,

I’m really sorry to hear that things haven’t been working out. If you haven’t yet done so, I would recommend going through the OVO complaints process here to resolve the issue before going to the ombudsman. If you have been overcharged and OVO can verify this, you’ll be able to get a refund for all the excess payments and your Direct Debit payments can be dropped back down to what it should be.

The agents on the complaints team are really good and you’ll get a dedicated complaints handler who will ensure this gets resolved quickly.

As for contacting the police, I wouldn’t recommend this approach as you’re unlikely to get very far. The police can only deal with criminal law and a billing error like this comes more under contract law, meaning it’s out of scope for them.

If you’d prefer to leave OVO anyway, that is an option as well, but I would strongly recommend using the complaints process first and seeing if that resolves the issue before deciding on your next move.

I hope this helps, but please feel free to let us know if you need any further advice.