UIG allocation issue

A to Z

UIG allocation issue

About us
About Xoserve

Our role and customers

What we do and who we work with

Our case studies

Explore how we underpin the smooth and reliable operation of the GB gas industry

Information for gas consumers

Advice for gas consumers and who to contact for help

Supplying services to Xoserve

Become an approved supplier, submitting invoices, our code of conduct
Strategy & governance

How we are governed

Information about how we are funded, governed and owned

Business plan

How we plan our budgets with customers, view our latest plan

Annual review

Get an update on our progress over the last financial year

Vision and strategy

Our vision for the future, strategic direction and objectives
Leadership

Xoserve Board

Steering the company strategically, ensuring strong governance and accountability

Xoserve Leadership Team

Proven leaders united by a collective passion for serving customers
Careers

Careers at Xoserve

Explore a career with us and view our latest vacancies
Products & services
Market entry/exit

Join/exit the gas market

Apply to participate in the gas market and the process for exiting

Market participant data

Market Domain Data (MDD)

Understand the market participant process, download the MDD document

Energy Identification Codes (EIC)

Apply for your unique ID in the EU Internal Energy Market (IEM)
Data services

Access to our data services

Connecting you to all our digital data services from one location

UK Link System

Connecting complex industry systems and accessing secure documents

Contact Management Service (CMS)

An online business-to-business service for managing contacts

Gemini System

A suite of online applications for managing the transport of gas

Data Discovery Platform (DDP)

Data visualisations for actionable insight
Gas Enquiry Service (GES)

An online service for accessing details about supply meter points

Information Exchange (IX)

A secure means of exchanging files

SwitchStream

An online tool to make new switching easier

Gas APIs

API services available to a range of customers
Service enhancements

Service Enhancements Programme

Enhancing and optimising the customer and user experience across our service estate
DSC support
Data Services Contracts (DSC)

DSC customer support

Update or make changes to your DSC contract, register or change your LSO

DSC extra services

Request specific or additional services under your DSC contract
DSC support

Customer Support team

Information on our Customer Support team and their constituency sessions
Change
Gas change

How we manage change

How we facilitate industry change, funding, view ChMC Change Budget

Change forums

Information about change forums

Change common queries

Questions that we regularly get asked about change
Customer changes

Customer change register

View the progress of customer change proposals

Change packs

Consulting on customer and industry change

Submit a change proposal

The application process for submitting a customer Change Proposal

UK Link releases

View the previous and current changes we’re making to UK Link

Gemini changes overview

An overview of all the current Gemini changes
Key projects

Project Trident

Modernising UK Link to future-proof the gas markets data infrastructure

Service Enhancements Programme

Enhancing and optimising the customer and user experience across our service estate
GRDA REC change

REC consultation responses

Retail Energy Code consultation responses, provided by Xoserve as the the Gas Retail Data Agent
Decarbonisation
Decarbonising gas

Decarbonisation Knowledge Centre

How we’re helping to facilitate the decarbonisation of gas

DeliveringDecarb

Our monthly newsletter covering all things decarbonisation

Decarbonisation forums

Explore and register for one or more of our decarbonisation forums
Decarbonisation projects

H100 Fife

A groundbreaking green hydrogen project led by SGN

Managing Different Gases

Exploring CDSP system impacts posed by decarbonisation scenarios

Real Time Settlement Methodology

A project to establish a fair, practical, and flexible billing system
Decarbonisation pillars

Hydrogen

Learn all about how hydrogen can decarbonise the UK's energy system

Biomethane

A renewable gas that can help decarbonise the natural gas grid

Blending gas

Mixing low-carbon gases such as hydrogen or biomethane with natural gas

Carbon capture and storage

Capturing industrial CO2 before it reaches the atmosphere

The future of gas

Learn about what the future of gas could look like in the UK
News & updates
News & updates

News

The latest industry news from Xoserve

Events calendar

Manage your diary with our annual events calendar

Live updates

View the latest notifications and status of industry issues

Planned outages

Our systems maintenance windows and outages
Issues Register

View the status of issues raised by customers
Learning Hub
Training & e-learning

Learning Hub

The central location for all your training needs.

Gemini Learning Management System

Get the best from Gemini with this range of e-learning materials
Help centre
Invoices

Invoice type, charges & VAT

Check your invoice with our charging statement documents

Credit Risk & Neutrality

Guidance on energy balancing and CDSP Credit Risk Management, neutrality and payment rules

File types and formats

Get help with understanding the file formats in your invoice

Supporting information files

How we use level 1 and 2 files to validate your invoice

Energy Price Guarantee (EPG)

Information about how Xoserve is supporting the Energy Price Guarantee
Supply points & metering

Submitting reads

How to submit reads, understand rejections and replacing a reading

Supply Point Administration (SPA)

Get help with SPA tasks for Shippers, Suppliers, IGTs and DNOs

Annual Quantity (AQ)

Find out your site’s AQ, how AQ is calculated, AQ correction process

M Number creation

How to create an M Number (MPRN) for a live supply point

Non-Standard Sites

Submission templates and response files for unique gas sites
Demand Attribution

Demand Estimation

Demand Estimation parameters and the timetable for producing them

NDM Nominations and Allocations

How we calculate NDM demand and the NDM Nomination Accuracy Report

Unidentified Gas (UIG)

How it’s calculated and shared out, National UIG charts
Support

How can we help?

View popular information, material and common queries about our services.

Raise a support request

Have a process query or technical issue?

Check an existing support request

Find out the status of an existing support request

Shipper and Supplier relationships

Information and processes for Shippers and Suppliers, with regards to their commercial relationships

Contact

Address and directions

Our office address and directions

Xoserve is the Central Data Services Provider for Britain's Gas Market

Discover more

Decarbonising the gas network

Watch our latest animation to see how we’re enabling collaboration, unlocking insights and supporting the transition to a cleaner, more resilient energy future.

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Access to our data services

Connecting you to all our digital data services from one location.

Discover more

BP26 Final Version

Read the final version of our Business Plan for 2026-29 (BP26) and find out how you can engage with our business planning process.

Discover more

Latest news

04 Jun 2026
SDS-2: translating strategy into delivery for the gas sector
01 Jun 2026
Gas Network Code Collaboration: Progression to Ofgem's Licensing Assessment
29 May 2026
DeliveringDecarb - May 2026