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Erroneous Large EAC/AA Annual Billed Unit

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Erroneous Large EAC / AA Annual Billed Unit

Guidance Note


This document provides an overview of how Annual Billed Unit (ABU) data is used by Elexon’s Large EAC/AA (LEA) system and details how you can determine and submit ABU data.

How is ABU Data Used?

Each month you should receive an erroneously large EAC/AA instance report, which lists all EAC/AAs for your organisation’s MPANs that exceed certain size thresholds. The EAC/AA instances listed in the report should be investigated and the erroneous instances identified and corrected.

If a particular MPAN has consistently high genuine consumption, then EAC/AAs associated with that MPAN may frequently appear in your erroneously large EAC/AA instance reports. To reduce the need to repeatedly investigate these MPANs, you can submit Annual Bill Unit (ABU) data, which will be stored in Elexon’s LEA system. The ABU value for an MPAN should be representative of normal annual consumption. It will be used by the LEA system in two ways:

    • Anytime a new EAC/AA instance for the MPAN is received, the LEA system will automatically flag it as genuine if the new EAC/AA is less than double the value of the Annul Billed Units. For example, if the ABU value is 300,000KWh then any EACs and AAs for that MSID up to 600,000KWh will be flagged as genuine; and

    • If the new EAC/AA instance is not within the ABU tolerance then it will continue to be flagged as erroneous and for the purpose of Elexon’s materiality calculations the ABU data will be used as a means of estimating the realistic consumption for the MPAN. Note, where ABU data is not held, the realistic consumption value is based on the profile class average consumption.

If an ABU value is incorrect (for example, if it is based on Gross Volume Correction rather than realistic consumption) it can lead to erroneous instances being incorrectly flagged as genuine. Or, where the instances continue to be flagged as erroneous, the error will be under estimated.

Do I have to provide ABU Data?

No, providing ABU data is optional. Some Suppliers choose not to submit ABU data because they would rather the MPANs were marked as ‘erroneous’ in their Erroneously Large EAC/AA instance reports until they have reviewed them and confirmed them as genuine to Elexon.

How do I determine the ABU value for an MPAN?

If you would like to submit ABU data, then when determining what ABU value to submit for an MPAN, the ABU value can be:

    1. Based on billed consumption for the MPAN;

    2. Based on estimated realistic consumption for the MPAN; or

    3. Rather than submitting an exact value for each MPAN, you can submit a general value for a group of MPANs. For example, small SME customers could be grouped together and given the same ABU value which would be based on realistic consumption for that group.

ABU values should never be based on abnormal consumption, such as Gross Volume Correction

How do I submit ABU Data?

Each month when you receive your Erroneously Large EAC/AA Instance Report, you should also receive a copy of the EAC/AA Material Calculator, along with an FAQ explaining how to use the calculator. The EAC/AA Materiality Calculator can be used to create a file containing ABU data for submission to Elexon. Files should be emailed to

Some notes on Elexon’s system

Elexon’s Erroneously Large EAC/AA (LEA) system has various parameters and rules which can affect the loading of ABU data. When submitting ABU data to Elexon, please bear in mind the following:

    • The LEA system will only store positive ABU values; therefore, if you submit a negative ABU value it will not be loaded.

    • Where the LEA System already has an ABU value for an MPAN, it will only load a new ABU value for that MPAN if the new value is higher than the currently held value. If you wish to reduce any ABU values please email and let us know. We will then delete the old values so that the new ABU values are able to load.

    • Where the LEA system has ABU data for an MPAN it will use that data regardless of whether it was submitted by the current Supplier or a previous Supplier. If you notice that an MPAN that has been incorrectly flagged as genuine because of unrepresentative ABU data submitted by a previous Supplier, please let us know and we will remove the ABU value from the system.

Need more information?

For more information please email, contact the BSC Service Desk or call 0370 010 6950.

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