Useful Operational Information

On this page you will find links to various sources of useful Gas Operational Information.

National Gas values its customer and stakeholder feedback, and in response is constantly looking to improve its service offerings.

As part of this, we have embarked on an initiative that helps bring together a wealth of useful, gas operational information.

The following page includes links to all kinds of information, most of which can actually be found elsewhere on our National Gas website.

We hope that the signposted information is of use to you and your colleagues, and urge you to get in contact if there is anything else that you would like us to include.

Gas Operations Contact Directory

To help you efficiently find the right person to talk to in relation to specific National Transmission System operational gas queries, we have developed the following contact list and directory. We have based it on the most common queries we receive from our customers. Its purpose is to make finding the right subject matter expert within National Grid, quicker and easier than ever before.

National Grid representative sitting at a desk in front of a computer with an out of focus office in the background


Please note that if your query relates to a home or domestic gas connection or meter exchange, please contact your network operator. You can find who your network operator is on the Energy Networks Association website.  

Download the directory

Transmission Operational Data

National Gas Transmission Data Portal

Our Gas Transmission Data Portal provides up-to-date and historic operational gas transmission data. View reports and data items over your chosen date range in table and graph formats - many of these are also available to export to XML or CSV format.

Visit our data portal.

We provide this information to reduce market uncertainty, ensure equal access to information, and increase information transparency. 


Calculated Linepack Utilisation - The report collates the hourly supply and demand flow notifications received from NTS connected sites to calculate the NTS Linepack minimum value in MCM that would result from these flow profiles. This is available on our Transmission Operational Data page under Supplementary Reports.

Calculated Linepack Utilisation Report

Linepack Presentation


NTS Operational Overview

National Gas owns and operates Britain's Gas National Transmission System (NTS). 



Xoserve has full responsibility as system manager and system operator of Gemini, on behalf of National Gas.

The following processes can be carried out within the Gemini application:

  • Gas Nominations
  • Gas Trades
  • Energy Balancing
  • NTS Entry Capacity Booking
  • NTS Entry Capacity Trading

The following processes can be carried out within the Gemini Exit application:

  • Long Term NTS Exit Capacity Applications
  • NTS Exit Capacity Transfers
  • NTS Exit Capacity Assignments
  • Daily NTS Exit Capacity Auctions
  • Constraint Management Actions
  • NTS Exit Capacity Invoicing

Other useful resources include:

Gemini Changes

Provides an overview of planned and previously delivered activities on the Gemini system.

View Gemini Changes


Gemini User Guide

View Gemini User Guide


Gemini Invoicing 

Information on Gemini invoicing file formats and how to access secure documents is found using the link below. 

Invoice File Format Info


Gemini e-learning

Go to Gemini e-learning


Gemini Support

View Gemini Support page 


Market participants have an obligation to publish ‘inside information’ in respect of businesses or facilities which they own or control (or are operationally responsible for) before they can trade on it. REMIT introduces, for the first time, a consistent EU-wide framework:

This service provides a centralised GB Platform for the publication of REMIT Inside Information notifications, supporting market participants obligated under Article 4 of Regulation (EC) No 1227/2011.

Market Participants can choose to add notifications either manually via a secure Provider Account or through Twitter.

Please note the responsibility for the publication of inside information remains with the Market Participant, it is therefore suggested all notification providers have contingency processes in place should this service be unavailable for any reason.

Visit National Gas REMIT web page

View REMIT Frequently Asked Questions

EIC Codes

An EIC is a unique code that facilitates cross-border exchanges and identifies different objects and parties relating to the IEM and its operations. This was introduced on a European basis and aids all aspects of trading.  As of the 1st of November 2015, a registered EIC will be required if you intend to trade on PRISMA, the European Capacity booking platform.

On 7 September 2015, Xoserve became the Local Issuing Office (LIO) for the UK and therefore is authorised to issue International and Local EIC Codes. This role was previously held by National Gas.

For more EIC Code information or further help and support, please visit the Xoserve website. 

Visit Xoserve - EIC Code webpage


To view the full list of current EIC Codes, follow the link below:

View Public GB EIC Library spreadsheet

Unidentified Gas (UIG)

Xoserve manages the central database holding all gas consumption points (Supply Points) and analyse and report key data.

Using this gas industry supplied data, Xoserve's daily processes calculate Unidentified Gas (UIG) levels. This is an amount of gas which cannot be directly attributed to any system user. A major part of our work is to support the gas industry to understand, manage and resolve UIG in a better way.

Visit Xoserve - UIG webpage


Here you will find information about the different types of maintenance activities carried out on the National Transmission System that may impact our customers (including how to raise customer initiated requests), in addition to contact information for our planning team and links to all our published maintenance documents:

Two National Grid maintenance workers repairing a gas pipeline


  • Winter Maintenance Programme (Annual 24 month view of planned maintenance)
  • Summer Maintenance Programme (Annual 36 month view of planned maintenance)
  • EU Harmonisation Capacity Summary (Impact on Interconnector capacity due to NTS maintenance)
  • Maintenance Programme Review (Review of previous years’ maintenance)
  • Deliverability with Respect to Planned Maintenance (Summary of daily maximum capability to flow gas from all NTS supply sources)


Go to Maintenance webpage


We have developed a suite of pre-recorded webinars to provide guidance to the industry to aid decision-making. We are conscious that many of our operational customers work non-standard hours, so we felt that pre-recorded webinars would be beneficial as these can be viewed flexibly at times to suit operational needs.

2018 Webinars

2017 Webinars

Should there be any other topic areas that you would like to see covered by our suite of webinars, please do not hesitate to contact the Operational Liaison Team:  [email protected]