Fractional CISOCyber Governance5-minute readSeptember 2025

When a Fractional CISO Is the Right Appointment

Boards approach the CISO appointment as a headcount question. The prior question is what governance structure cybersecurity leadership requires, and whether a permanent appointment is proportionate to the organisation's scale, risk profile and current circumstance.

Four specific situations make a fractional engagement the right structure. In each, the need for senior cybersecurity leadership is genuine and a permanent appointment either cannot be made in time or is not sized for the requirement.

The governance question behind the appointment

The appointment of any C-suite role begins with a definition of what accountability it carries and what structure it sits within. For cybersecurity leadership, those questions are often deferred until after the decision to hire has already been taken.

A permanent CISO appointment is built around a specific assumption: that the security leadership requirement is ongoing, full-time and proportionate to a C-suite cost. That assumption holds for many organisations. For others, the requirement is defined in time, limited in scope, or does not justify a permanent appointment at that cost point. In those situations, a fractional engagement is the appropriate structure.

Four situations where a fractional engagement is the right structure

In each, the need for senior cybersecurity leadership is genuine and a permanent appointment is either unavailable in time or disproportionate to the requirement.

Post-incident
Following a significant incident, an organisation needs senior cybersecurity leadership quickly. A permanent appointment typically takes three to six months. A fractional CISO provides board-level accountability and programme ownership during the recovery period while a longer-term structure is determined.
Regulatory programme
CRA and ISO 27001 require senior cybersecurity leadership throughout programme delivery: risk assessment, governance design and technical direction across workstreams. Many organisations pursuing these programmes have no existing CISO. Once the programme closes and an operating model is in place, the function can be maintained at lower cost. A permanent appointment sized for the delivery period exceeds what the steady state requires.
M&A
Acquisitions require senior security judgement for due diligence, integration planning and the period immediately after close. Once integration is complete, the requirement closes with it. A permanent appointment for a time-limited engagement is the wrong structure.
Below the headcount threshold
An organisation that carries genuine cyber risk but cannot justify a full-time C-suite appointment needs senior cybersecurity accountability at proportionate cost. A fractional engagement provides that accountability without the overhead of a permanent hire.

What the engagement must define before it begins

Three things need to be defined before a fractional CISO engagement begins.

Scope of accountability
What the fractional CISO owns: which decisions require their sign-off, which risks sit within their brief, and where the boundary with internal management lies. An engagement that leaves this undefined places accountability imprecisely.
Reporting line
Where the fractional CISO sits in the governance structure. A fractional engagement that operates below the level of direct CEO or board access does not carry the authority that cybersecurity leadership requires. The reporting line should be the same as for a permanent appointment.
Exit and handover
How the engagement ends and what it leaves behind. Whether the conclusion is a permanent appointment, a reduced ongoing engagement or a transfer to internal ownership, the handover should be specified at the outset.

How this affects your organisation

For C-level executives and boards deciding how to structure cybersecurity leadership, the four situations above define when a fractional model serves the requirement. Outside those situations, a permanent appointment is the appropriate structure.

The decision is a governance question. The structure of the appointment determines who carries accountability for cybersecurity leadership, at what level of authority, and for how long. That accountability needs to be clearly placed before the engagement begins.

If you are considering how to structure cybersecurity leadership for your organisation, an advisory call is a useful starting point.