Data and operations

These pages contain information for users of the National Transmission System (NTS). Here you will find out how we balance the NTS, the latest operational data and real time flow data, maintenance plans, information about gas quality, and entry and exit capacity details and reports.


How we handle entry and exit capacity, including how to bid for entry capacity and apply for exit capacity, as well as current and historical capacity data.

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Constraint management

How we manage gas constraint actions and materials to help you understand localised system management.

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Transmission operational data

Data for industry analysts including operational data to reduce market uncertainty, ensure equal access to information, and increase information transparency.

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Essential undertaking as part of our role to keep the National Transmission System (NTS) safe, fit for purpose and operating efficiently and economically.

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Operational news

On this page, you will find the latest news and announcements relating to gas operations and data. Please refer to this page for industry updates, data changes and outages.

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Operational forum

Regular meetings with gas customers to discuss the operation and performance of the Network Code energy balancing and capacity systems.

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How we regulate gas quality in the National Transmission System (NTS) as a safety measure, including details on gas contents and components.

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Calorific value (CV)

How the calorific value (CV) of gas is calculated and how we determine the amount of energy transported by shippers and suppliers, which is used to bill gas consumers.

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Gas query 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.

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