Final meter reading given to new supplier they used estimate instead

Unfortunately I don't think it answers my questions, which concerns the process that should be followed when a customer submits an actual reading (in the correct manner) when switching supplier.

From memory, the customer reading is submitted to a 3rd party (Data Aggregator??) for validation and can be rejected if it does not fall in line with the previous Data Collectors previous validated reads or is not submitted in the correct time frame. The 3rd party (DA) then generate an estimated read based on what they expect the reading to be and if their is any dispute this can be raised at a later time.

I'm presuming, if the OP submitted their read on time, the previous DC have validated an estimated read higher than the customer's read given, or Eon didn't submit the read in time. As previously described the estimated read can only disputed if the difference is greater than a set industry level

Not sure how Coop could have possibly made even a reasonably accurate estimate in my case. I was asked for a meter readings mid April which were used to produce a bill. Didn't receive any further communication from Coop until I'd advised them I was leaving in Mid September.

The estimated reading i'm talking about is regarding the Data Aggregator systems which are completely separate from the reads you would see on your bill. The readings any customer sees on their bills are produced through your suppliers billing systems and should be entered according to how often the meter is read by the customer or meter reader or how often prepayment meters are topped up, usually, every quarter or 6 monthly period. The Data Aggregator uses a seperate system that are used to ensure that the supplier is paying the correct amounts to the relevant generation/distribution provider in your area and use a combination of customer reads, meter readers input and system generated estimates based upon what they would expect your consumption to be.

In your scenario, its possible the DA has estimated a reading higher than the reading you submitted to Eon as your opening read and have rejected this proposal. This system was put in place to make sure neither supplier billed you for the same energy used and would only be amended if the difference between the correct reading was greater than 250 units. I know its not helpful but these rules were put in place when the energy sector was privatized and the cost of Electricity and Gas meant the difference was a negligible amount. AFAIK the thresholds for Gas and Electricity disputes hasn't changed since then.

Although the way you describe Eon's "system error" could also imply they messed up and didn't submit your meter reading on time which led to the estimated transfer reading being produced although you could have spoken to an adviser who didn't know the transfer process correctly and gave you the wrong information/soundbite.