Critical national infrastructure

The National Risk Register 2025 uses the term without a single definition, but its usage is consistent. Of financial market infrastructures it says that some "constitute critical national infrastructure (CNI), as they provide services essential to the UK economy/functioning of state", and that companies providing the UK's CNI "are high-profile targets to state and non-state actors". It describes telecommunications as "part of the communications critical national infrastructure (CNI) sector", comprising fixed-line, mobile and internet infrastructure. Space-based services such as satellite communication and remote sensing are "components of the UK's critical national infrastructure (CNI) that enable many essential services to function", and satellite position, navigation and timing signals underpin "almost all the UK's critical national infrastructure (including energy, emergency services and healthcare)".

The register counts operators of CNI among its intended readers, as businesses "who have a need to understand the most serious risks that could impact their business continuity". It notes that insolvencies may create secondary risks to CNI and that CNI organisations face malicious cyber attack.

The UK Government Resilience Action Plan 2026 implementation report places "essential services and critical national infrastructure (CNI)" within whole of society resilience, alongside local responders, the voluntary, community and faith sector and the public.