About Us | GMO Northern Ireland (en-GB)

Who Are We

The Gas Market Operator for Northern Ireland (“GMO NI”) operates the natural gas transmission market in NI on behalf of the four gas transmission operator (“TSOs”), GNI(UK), Premier Transmission Limited (“PTL”), Belfast Gas Transmission Limited (“BGTL”) and West Transmission Limited (“WTL”).

Established in October 2017 through a licence obligation placed on the TSOs, GMO NI is a contractual arrangement between parties, and consists of seven employees based in Belfast. GMO NI is the primary interface with network users and manages activities such as administration of both the NI Network Gas Transmission Code and the NI gas operational IT system, oversees and administers network user charging and associated revenue redistribution to the TSOs, and is responsible for monitoring, managing and implementation of any gas transmission market change for NI.

Since December 2025, GMO NI has taken on a new gas network planning remit which builds upon the key role GMO NI currently plays as the single point of contact for operating the gas transmission market in Northern Ireland. Working closely with government and regulators and collaborating with industry stakeholders, GMO NI will play a leading role in the Northern Ireland gas planning function, supporting the delivery of a reliable and more sustainable energy supply for Northern Ireland’s low carbon future.

Northern Ireland’s electricity and gas transmission system operators have signed an agreement to deepen collaboration and the alignment of investments in both the electricity and gas systems.

A memorandum of understanding has been agreed between SONI, the electricity transmission system operator for Northern Ireland and Gas Market Operator Northern Ireland (GMO NI) on behalf of gas transmission system operators Mutual Energy and GNI(UK). This agreement will facilitate closer collaboration, expert and transparent knowledge sharing, more regular engagement, and intelligence gathering to support holistic energy planning, helping safeguard security of supply and decarbonisation opportunities.

GMO NI'S Vision

To be recognised as the efficient and transparent operator of Northern Ireland’s Gas Transmission Market. In line with this vision, GMO NI staff carry out there daily business activities underpinned by GMO NI’s core values…

Transparency

We will operate transparently, engaging with our stakeholders in relation to our activities and our deliberations.

Efficiency

We will operate efficiently, adding value and avoiding unnecessary costs.

Integrity

We will be recognised for doing the right thing.

Teamwork

We will work as a team internally and through our industry engagements.

Performance

We will deliver to our stakeholders the quality service they expect and foster a culture of continuous improvement in everything we do.

GMO NI Background

Previously the gas transmission market in Northern Ireland had been operated by four separate Transmission System Operators (TSOs), PTL, BGTL, WTL and GNI (UK).

In the interests of streamlining the interaction between gas suppliers and TSOs, the Utility Regulator has sought to create a single system operator to manage all the commercial functions on behalf of the TSOs in Northern Ireland.

The TSOs have now put in place arrangements to establish GMO NI and ensure there is a single interface for dealing with all commercial aspects of operating the transmission networks.

The TSOs are still responsible for operating and maintaining their respective transmission networks.

Functions and Benefits of GMO NI

The main purpose of GMO NI is to simplify the processes for gas suppliers by providing a single point of contact for all commercial activities.

This is delivered through a new single IT gas transmission management system (DELPHI), a consolidated single code and a single team to manage all commercial processes and address any queries from suppliers.The GMO NI will manage a range of functions including:

Market Operations

(capacity bookings, nominations, allocations)

Procurement and administration/operation of a single IT system

Single Code administration and interface with UREG on Code/market related issues

Invoicing function – Shippers will receive all invoices issued by GMO NI and not from TSO’s

Administration of energy balancing charges

First point of contact for new connections

Production of Market Reports –

ensuring transparency

Although the new arrangements under GMO NI should benefit all stakeholders in Northern Ireland’s gas transmission market, there are very clear benefits for gas shippers. These include:

Single IT System: Each Shippers transactions are consolidated into one IT system.
Single Operating Code: GMO NI will manage a single Code of Operations
One Stop Shop. Shippers using the NI Transmission system will interface with one entity, the GMO NI, in relation to market operations.
Avoidance of duplication of tasks and therefore delivering efficiencies

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