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XRN 4645
The rejection of incrementing reads submitted for an Isolated Supply Meter Point (RGMA flows)

Last Updated
14 Dec 2020
Release Type
Implementation Date
29 Oct 2020
Proposer Xoserve Impacted DSC service area

Service Area 3 (Previous Dec 18 – Mar 21)

Record/submit Data in Compliance with UNC

Customer Change Team Leader


An issue has been identified where following Project Nexus Implementation Date (PNID). Xoserve has received in excess of 3500 RGMA transactions where the User has provided a Meter Information Notification (JOB transaction) or Meter Information Update Notification (UPD transaction) to reverse an isolation of a Capped or Clamped Supply Meter Point but that the reading provided in the transaction has incremented from the reading provided at isolation.

When a User indicates that the Supply Meter Point is isolated, they are indicating that it is not capable of flowing gas (UNC Section G 3.4), and therefore an incrementing reading is not expected following such isolation. Other reading processes reject any incrementing readings.

Where a User submits an RGMA transaction to reverse the isolation the initial JOB or UPD transaction is currently being processed, and the UK Link system is being updated with the Metering Information contained within the transaction. However, given that the User has informed the CDSP that the Supply Meter Point is not capable of flowing gas this has been excluded from allocation processes, and therefore any attempt to reconcile the Supply Meter Point creates an error within the invoicing process. As such these items are being currently excluded from the Amendment invoice.

This is causing issues with the daily volume and energy calculated for reconciliation.

A proportionate solution needs to be developed to support the ability for Users to retain the ability to notify where a Meter is not capable of passing gas (UNC Section G3.4) but reduce the risk to downstream processes and the wider industry.

As of 07/05/2020 this change has been split into two parts, part A and part B. The reasoning for this is so that the rejection code element of the change, which has previously been ratified by DSG and will prevent the occurrence of the exception BI49 by rejecting an RGMA transaction for an isolated site that contains an incrementing read, can be deployed under XRN4645A in order to support the implementation of the Urgent COVID-19 related modification 0723. Part B, which will look to develop an enduring process to support the new rejection code, will continue through the change process.

XRN4645 part B was withdrawn as, following further investigation, no viable change could be identified to improve the process. For information, the new rejection for incrementing reads on isolated meter points (within RGMA files) was implemented through XRN4645a.

Impacted Customer Types

  • Shipper
  • UIP


Document title Last updated Type
XRN4645 - Part B - CP 04/Aug/2020 PDF
XRN4645A - BER 08/Jul/2020 PDF
XRN4645 - Part A - CP 16/Jun/2020 PDF
4645 HLSO 13/Jan/2020 PDF


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