Unlocking More Value From NUAR: User Access Expansion Begins

Underground asset data is a crucial national data set, and the more comprehensive it is, the greater the value it can unlock across emergency response, planning, development and infrastructure delivery. This is why the government is looking to expand the National Underground Asset Register’s (NUAR) current user base.

To support this work, we are excited to announce that the secure NUAR Sandbox test environment is now available, for new users to test use cases and gather evidence.

This blog post covers the following:

• Who could benefit from expanded access to NUAR
• How to engage with Ordnance Survey (OS) and test your use cases
• What you get from engaging with the NUAR Test Services
• How the NUAR Test Services will be delivered, including what testers can expect from OS and what OS needs from participants

In January 2026, the Government Digital Service (GDS) announced their plans to broaden access to the National Underground Asset Register (NUAR), to new user groups and for new use cases, and different ways of accessing the data in NUAR, such as an API. This followed an extensive Discovery project with potential users, engagement with asset owners and industry stakeholders, and analysis of the opportunities and risks associated with broader access to underground asset data. The discovery phase highlighted how broadened, yet secure access would deliver substantial economic, safety, and operational advantages.

Building on that evidence, we are now moving forward from policy development into testing and delivery. The NUAR sandbox will be used to identify the technical solutions needed to enable these priority use cases, gathering further evidence where required and informing any future policy, legislative or regulatory changes needed to enable wider access.

Testing will be done in a secure separate sandbox environment that doesn't use any real live data. Throughout the user access expansion, ensuring data security will continue to be a top priority.

Who could benefit from expanded access to NUAR?

The government has committed to widening access to NUAR for a broad set of users, including emergency services and other public sector bodies, asset owners for wider core business purposes, and organisations planning or carrying out development activity, and different ways of accessing the data in NUAR, such as an API.

This could include:

• Emergency services could use NUAR to see what lies beneath a site while responding to an incident, helping crews make faster and safer decisions at gas leaks, fires, floods and road traffic collisions, and to plan for emergencies in advance.
• Other public sector bodies, such as local authorities, could use NUAR to support statutory functions, local planning, infrastructure coordination, resilience activity and other public service outcomes.
• Asset owners and their service providers could integrate NUAR more widely across their own systems and workflows, for example through an API, so that a consistent view of underground assets is available to teams working beyond street works, to improve network planning, deployment, customer service and operational efficiency, where this does not negatively affect market competition.
• Developers could use NUAR to identify underground assets early in the design and planning of a scheme, such as property, infrastructure or renewable energy, reducing the risk of late design changes, delays and asset strikes on site.
• Organisations working close to underground assets could use NUAR to plan activity that may affect those assets even where the ground is not physically broken, such as moving heavy plant or storing materials on site.
• Landowners could use NUAR to understand the underground assets on or near their land before undertaking works or commissioning activity.

Who are we looking to engage with?

We welcome involvement from organisations who are interested in underground asset data.

We are particularly interested in hearing from organisations who work with, on behalf of, or alongside asset owners or have an operational need for underground asset data beyond NUAR’s current user community of asset owners and their street work contractors. For the current asset owner users using NUAR, the benefits of these test services are to expand how they can use NUAR, such as improving infrastructure planning, deployment, customer service, and operational efficiency.

Organisations interested in participating are invited to submit a “NUAR user access expansion initial interest submission” form here You will be asked to provide your name, organisation and email address. Upon checks you will then have the “Submit a Use Case for NUAR Access Expansion” form shared with you, where you will be asked to provide your nominated contacts and high-level use cases.

Expressions of interest will be assessed and prioritised with suitable candidates invited to participate in sandbox testing as capacity allows. We will initially be prioritising interest from the emergency services to explore how NUAR can support their critical services. Insights gathered through testing will help inform future decisions on the potential expansion of access to NUAR. 

Complete the “NUAR user access expansion initial interest submission” form

What do you get from engaging with the NUAR Test Services?

The value from participating includes:

1. Get early access to explore new NUAR capabilities
2. Support the provision of wider NUAR user access
3. Shape future service design to meet your operational requirements
4. Opportunity to inform policy design
5. Ensure that NUAR can be better integrated into your organisation's operational practices.

How will the NUAR Test Services be delivered?

The NUAR test services to expand user access will be delivered through a structured, evidence-led testing programme. This means OS will work with organisations to understand their use cases, assess whether NUAR could support them, and test priority scenarios in a safe environment.

There are two main delivery mechanisms:

1. Outreach and Engagement

The outreach element is how OS will build on the previous discovery work by identifying, understand and prioritising potential use cases for expanded NUAR access. Organisations are invited to submit a “NUAR user access expansion initial interest submission” form here You will be asked to provide your name, organisation and email address. Upon checks you will then have the “Submit a Use Case for NUAR Access Expansion” form shared with you, where you will be asked to provide your proposed use case and expected benefits. This information will help OS understand who needs access, what they need to do, what data or functionality may be required, and what benefits or risks need to be considered. Outreach may include workshops, interviews, surveys and follow-up discussions so that user needs are captured clearly and consistently.

2. Sandbox testing

The 'Sandbox' is a controlled test environment where selected organisations can explore NUAR capability safely using synthetic data. It is separate from the live NUAR service and is designed to test use cases, user journeys, access routes and potential new functionality without affecting live operations. Sandbox testing may include testing different ways of accessing NUAR, such as user interface options, Application Programming Interfaces (APIs), and role-based access. The aim is not simply to demonstrate technology, but to gather reliable evidence about whether a use case is valuable, feasible, secure and proportionate.

The process is planned to follow these steps:

1. Register interest – an organisation can submit their use case/s for NUAR access.
2. Initial review and prioritisation – the use case is reviewed to understand its relevance, urgency, policy value and suitability for further assessment.
3. Use case assessment – the user need, expected benefits, data requirements, access assumptions and risks are explored in more detail.
4. Onboarding to Sandbox testing – where a use case is suitable, participants are onboarded into a controlled testing cycle with clear guidance and agreed support framework.
5. Testing and feedback – participants run agreed scenarios, record outcomes, and provide feedback.
6. Evidence and recommendations – findings are reviewed and used to inform future NUAR service design, policy decisions and any further testing requirements.

What testers can expect from OS:

1. Sandbox configuration, access management and test data availability.
2. Support available from OS before, during and after testing.
3. Participant onboarding materials, user guides and briefing sessions.
4. Process for raising questions, defects and enhancement requests.

What OS needs from participants:

1. Named contacts for operational, technical and governance coordination (including availability during test windows).
2. Defined use cases and success criteria (e.g., key workflows, data quality expectations).
3. Test participation in agreed cycles by executing scenarios, logging outcomes, and joining review checkpoints.
4. Feedback and sign-off, with timely validation of findings.