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XRN 5170
MOD0723 (Urgent): Use of the Isolation Flag to identify sites with abnormal load reduction during COVID-19 period

Last Updated
27 May 2021
Release Type
Implementation Date
12 May 2020
Proposer Northern Gas Networks Impacted DSC service area

Service Area 1 (Previous Dec 18 – Mar 21)

Manage Supply Point Registration

Customer Change Team Leader


Where a Shipper User identifies a site as having nil or de minimis consumption as a direct result of it restrictions resulting from the Coronavirus Act 2020, Shipper Users will be able to apply a flag to the registered Supply Meter Point to be marked as Isolated. 

The periods during which the a relevant Supply Point is deemed to be in a COVID-19 period for the purposes as outlined in COVID-19 specific Modifications are: Where any of the powers as laid out in the Coronavirus Act 2020 Schedule 22, (Powers to Issue Directions Relating to Events, Gatherings and Premises) are enacted for all or any of England, Scotland, Wales, then this will be deemed to be a COVID19 Period for UNC purposes for the relevant Supply Meter Point when the Supply Meter Point is situated in the a part of the UK for the period during which any of the powers enacted relevant to that part of the UK are in force. 

Whilst sites have an Isolation flag under during the COVID-19 period, Re-establishment rule UNC TPD G 3.7.1 ‘Where a Supply Meter Point has been Isolated in accordance with paragraph 3.5.3 and the Transporter or the CDSP becomes aware that gas is capable of being off taken at that time (without further action being taken) from the Total System at such point then the Transporter or (as the case may be) the CDSP will notify the other, and the CDSP shall notify the Registered User of such fact’ will not be applicable. 

Shipper Users will only be able to apply for the relevant COVID-19 period as specified above.

Shipper Users are obligated to request an immediate removal of the Isolation flag should they become aware of usage of gas increasing at the site above the de minimis level of 2.5% of the pre COVID-19 period.

Shipper Users are obligated to request an immediate removal of the Isolation flag should the site no longer be classed as being deemed to be in a COVID-19 period, as per the UNC definition for this purpose set out in this Modification and UNC Transition Document.

Any meter read liabilities will be suspended, where the Isolation flag is set for conditions met under this Modification. 

Impacted Customer Types

  • IGT
  • Shipper
  • DNO


Document title Last updated Type
XRN 5170 - CP 14/May/2020 PDF


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