Breaking Down "Fractional CISO"
"Fractional"
A fraction of their time. Rather than full-time employment, a fractional CISO dedicates part of their capacity to your business—typically 1-3 days per week or equivalent hours.
"CISO"
Chief Information Security Officer. The senior executive responsible for cybersecurity strategy, risk management, compliance, and protecting the organization from cyber threats.
Fractional CISO vs Virtual CISO
You'll often see "vCISO" (virtual CISO) used alongside fractional CISO. The terms are largely interchangeable:
| Term | Emphasis | Common Context |
|---|---|---|
| Fractional CISO | Part-time commitment | Aligns with fractional executive trend |
| Virtual CISO (vCISO) | Remote delivery | Cybersecurity industry term |
| CISO-as-a-Service | Service-based model | Managed security providers |
| Part-Time CISO | Time commitment | General business term |
What Does a CISO Actually Do?
According to the National Cyber Security Centre, organizations need security leadership to manage increasingly complex cyber risks. A CISO provides that leadership.
Security Strategy
Develop and implement cybersecurity strategy aligned with business objectives and risk appetite.
Risk Management
Identify, assess, and manage cyber risks. Communicate risk to the board in business terms.
Compliance
Ensure compliance with regulations (GDPR, NIS2) and standards (ISO 27001, SOC 2, Cyber Essentials).
Incident Response
Prepare for and manage security incidents. Develop response plans and lead during breaches.
Security Program
Build and mature the overall security program: policies, awareness, technology, and people.
Why Fractional CISO Makes Sense
The Problem
- Full-time CISOs cost £120,000-£200,000+
- Cyber expertise is scarce and expensive
- SMEs can't justify full-time security exec
- But security leadership is increasingly required
The Solution
- Fractional CISO at £2,000-£6,000/month
- Senior expertise without full-time cost
- Scalable as security needs grow
- Meets customer and compliance requirements
When to Hire a Fractional CISO
Good Fit:
- SMEs handling sensitive data
- Companies pursuing ISO 27001 or SOC 2
- B2B businesses with security questionnaires
- Regulated industries (finance, health)
- Post-breach recovery
May Need Full-Time:
- Large enterprises (500+ employees)
- Critical national infrastructure
- Financial services (FCA regulated)
- Defense/government contractors
Cost Comparison
1-3 days per week engagement
Salary + benefits
Summary: A fractional CISO (or vCISO) is a part-time Chief Information Security Officer who provides cybersecurity leadership 1-3 days per week. "Fractional" means you get a fraction of their time at a fraction of full-time cost—ideal for SMEs needing security leadership.