Understanding the NCSC Cyber Assessment Framework (CAF): What It Is, Why It Matters, and Who It’s For
Updated: Aug 12
Cyber threats continue to evolve in scale, sophistication, and impact—especially for organisations delivering services the UK depends on every day. To help these organisations build meaningful, measurable cyber resilience, the National Cyber Security Centre (NCSC) created the Cyber Assessment Framework (CAF): a structured, outcome‑focused model for assessing and improving cyber security across essential functions.
The CAF has become a cornerstone of UK cyber resilience, underpinning regulatory regimes such as the Network and Information Systems (NIS) Regulations and providing a consistent way to evaluate cyber risk management across critical sectors.
What the NCSC CAF Is
The Cyber Assessment Framework (CAF) is a comprehensive, principles‑based model designed to help organisations understand how effectively they manage cyber risks to their essential functions—the systems and services whose disruption would have significant national or societal impact.
Rather than prescribing specific technical controls, the CAF focuses on outcomes. It defines what good looks like across four high‑level security objectives:
1. Managing Security Risk (Objective A)
Ensuring governance, risk management, and organisational structures support strong cyber resilience.
2. Protecting Against Cyber Attack (Objective B)
Implementing proportionate protective measures to reduce the likelihood of compromise.
3. Detecting Cyber Security Events (Objective C)
Ensuring the organisation can identify potential cyber incidents quickly and effectively.
4. Minimising the Impact of Cyber Incidents (Objective D)
Ensuring robust response and recovery capabilities to reduce harm and restore essential services.
These objectives are broken down into 14 principles, each supported by Indicators of Good Practice (IGPs) that help organisations benchmark their maturity and identify gaps.
Why the CAF Is Important
The CAF plays a critical role in strengthening the UK’s cyber resilience. Its importance stems from several key factors:
It protects essential services
CAF is designed for environments where cyber incidents could cause serious disruption—energy networks, healthcare systems, transport infrastructure, and more. It ensures organisations have proportionate controls to defend against both common and advanced threats.
It supports regulatory compliance
CAF underpins cyber regulation in multiple sectors, including the NIS Regulations. Regulators use CAF to assess compliance, and organisations use it to demonstrate they meet required resilience levels.
It avoids tick‑box security
CAF is outcome‑driven. It focuses on whether an organisation can actually manage, detect, and respond to cyber threats—not whether it has completed a checklist.
It improves national visibility of cyber risk
CAF provides a consistent assessment model across sectors, enabling government and regulators to understand systemic risks and prioritise improvements where they matter most.
It drives continuous improvement
CAF’s Indicators of Good Practice help organisations identify weaknesses, plan remediation, and track progress over time.
Who the CAF Is Aimed At
The CAF is primarily intended for organisations that operate essential services—those whose disruption would significantly impact daily life, national security, or public safety.
Typical sectors include:
Energy (electricity, gas, oil)
Healthcare (NHS trusts, critical medical systems)
Transport (rail, aviation, maritime)
Digital infrastructure (ISPs, data centres)
Water and waste management
Government departments and public bodies
Critical National Infrastructure (CNI) organisations more broadly
CAF is also used by:
Regulators and competent authorities
Organisations delivering essential functions on behalf of government
Managed service providers supporting critical systems
CAF Profiles (Basic and Enhanced) allow tailoring based on the threat landscape—ranging from common cybercriminal activity to highly capable state‑sponsored actors.
CAF‑Aligned Checklist for a Generic Organisation
This checklist provides a practical, high‑level way for organisations to assess their alignment with CAF principles. It is suitable for internal self‑assessment or early‑stage readiness reviews.
A. Managing Security Risk
A1 Governance
Clear cyber security roles and responsibilities defined
Senior leadership actively engaged in cyber risk decisions
Cyber security integrated into organisational governance
A2 Risk Management
Documented cyber risk management process
Risks to essential functions identified, assessed, and reviewed
Risk treatment plans in place and monitored
A3 Asset Management
Inventory of systems, services, data, and dependencies
Identification of essential functions and supporting assets
Ownership and lifecycle management defined
A4 Supply Chain Security
Supplier risks assessed and monitored
Security requirements included in contracts
Assurance mechanisms in place for critical suppliers
B. Protecting Against Cyber Attack
B1 Secure Architecture
Network and system architecture designed for resilience
Segmentation and least privilege principles applied
B2 Secure Configuration
Baseline configurations defined and enforced
Regular patching and vulnerability management
B3 Identity & Access Control
Strong authentication and access controls
Privileged access tightly managed and monitored
B4 Data Security
Sensitive data identified and protected
Encryption used appropriately
Data retention and disposal policies enforced
B5 Resilient Technology
Backup strategy aligned to essential functions
Redundancy and failover mechanisms tested
C. Detecting Cyber Security Events
C1 Security Monitoring
Logging and monitoring implemented across critical systems
Alerts triaged and investigated promptly
C2 Anomaly Detection
Baselines established for normal behaviour
Mechanisms in place to detect deviations
D. Minimising the Impact of Cyber Incidents
D1 Response & Recovery Planning
Documented incident response plan
Clear roles, communication channels, and escalation paths
Regular exercises and simulations
D2 Lessons Learned
Post‑incident reviews conducted
Improvements tracked and implemented
Closing Thoughts
The NCSC Cyber Assessment Framework is more than a compliance tool—it’s a practical, outcome‑driven model for building genuine cyber resilience. For organisations delivering essential services, CAF provides clarity, structure, and a shared language for managing cyber risk in a world where threats continue to evolve.
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