We have full system responsibility for Gemini and Gemini Exit on behalf of National Grid.

The Gemini System is a suite of web applications for managing the transportation of gas through the pipeline network.

Gemini Login Details



Gemini Technical Documents

File formats

The Gemini System

Gemini is a suite of online applications used by National Grid and its business associates to manage the transport of gas through pipelines.

Gemini includes applications for essential gas market processes:

  • Capacity Management
  • Capacity Trading
  • Commercial Balancing
  • Billing

Each of these applies to a specific phase in the transfer of the gas, managing processes for:

  • Entry Capacity and Entry Capacity Invoicing
  • Energy Balancing and Energy Balancing Invoicing
  • Exit Capacity and Exit Capacity Invoicing

The Gemini suite is separated into two different applications:

  • Gemini
  • Gemini Exit

We have full responsibility as system manager and system operator of the Gemini System on behalf of National Grid.

Logging into Gemini

The Gemini application is only supported by Internet Explorer 11 (IE11). It also requires the installation of:

As Gemini uses the Citrix application to run, two User IDs are needed:

  • One ID is used to log into Citrix
  • One ID is configured and used for Gemini

Gemini works on a role-based system, with each User ID given roles relevant to the duties they need to perform on the system.

Gemini re-platforming

As we move to a new 'virtualised' Gemini infrastructure, this short video will walk you through the changes needed to Citrix – to ensure continued access to the Gemini production environment.

Accessing Gemini

Before requesting access to Gemini, please read the Gemini User Role Descriptions information. Once you have decided on the correct user roles, your Local Security Officer (LSO) can arrange Gemini access for you. Contact them and ask them to return the Gemini Access Form, requesting the:

  • creation of your user IDs
  • required roles for your ID

Your LSO is responsible for all account administration, including:

  • creations and deletions
  • permissions and roles
  • password resets

If you need to know who your LSO is, our Service Desk can help:

Gemini Help Button

A Help Button has been introduced within Gemini and the Citrix page.

The button lets Users view:

  • Frequently Asked Questions about Gemini processes
  • Basic information about the functionality in Gemini

Download the Gemini FAQs Button screen guide.

Gemini Technical Documents

View the Gemini Technical Publications in the Resource Library.

Gemini invoicing file formats are on the non secure UK Link Documentation SharePoint.

What Gemini Does

To put, or flow, gas into the National Transmission System (NTS), Users need to get System Entry Capacity. Gemini is used for this process, with the following functions:

  • GB/EU Entry Trading
  • GB/EU Entry Capacity Transfers
  • GB/EU Entry Capacity Auctions
  • GB/EU Invoicing
  • GB/EU Entry Nominations
  • GB/EU Entry Allocations

What Gemini Exit Does

To take, or flow, gas out of the NTS, Users need to get NTS Exit Flat Capacity. Gemini Exit is used for this process, with the following functions:

  • GB/EU Exit Capacity Trading
  • GB/EU Exit Capacity Transfers
  • GB/EU Exit Capacity Auctions
  • GB/EU Invoicing

Gemini invoicing file formats are available from the UK Link Documentation secure SharePoint.

Gemini Maintenance

UPDATE 19th June 2020: Gemini Re-Platforming Project

There will be an extended Gemini system outage on Sunday 5th July to implement planned changes.  The extended outage window is anticipated to be between eight to twelve hours.  The timescale for implementation are:

  • 03:00 – 05:00 usual Gemini Maintenance Window
  • 05:00 – 13:00 extended outage

If a rollback is required, this would take place from 13:00 – 17:00


The maintenance window for Gemini runs every day.

From Monday to Saturday, the service will be unavailable from 3:15am – 4:15am.

On Sundays, the service will be down for maintenance from 3:00am – 5:00am.

If you are trying to access Gemini outside of the maintenance windows and are unsuccessful, please raise a ticket with the Xoserve Service Desk by emailing

View all of the Gemini event information in our calendar by clicking here

View maintenance and system outage information for all our systems.

Frequently Asked Questions

Read all FAQs

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