What does a fractional cfo do?

A Fractional CFO is a fully qualified, experienced Chief Financial Officer who works with a business on a part-time basis — typically one to two days per week — providing CFO-level strategic finance leadership without the cost or the commitment of a full-time permanent appointment. The fractional CFO model allows businesses at an earlier stage of growth to access board-level finance expertise that would otherwise be unaffordable, while maintaining the flexibility to scale the engagement as the business grows and its needs change.

The role is frequently misunderstood. A Fractional CFO is not a consultant engaged for a one-off deliverable. They are not a part-time bookkeeper or Finance Manager. And they are not a cheaper substitute for a Finance Director whose other title happens to be CFO. The Fractional CFO is a genuinely strategic, board-level finance professional who has agreed to invest their time and expertise in multiple businesses simultaneously rather than committing to one full-time role. The best Fractional CFOs are former full-time CFOs who have deliberately chosen the portfolio model — and they bring to each engagement the full depth of experience they accumulated in those full-time roles.

What a Fractional CFO Does: The Core Activities

Strategic Financial Planning

The primary contribution of the Fractional CFO is strategic financial input at board level. This is the dimension of finance leadership most commonly missing from businesses below £20m revenue that do not have a full-time FD or CFO. In its absence, the CEO typically makes the business’s most important financial decisions — how to allocate capital between competing initiatives, whether the business can afford the next phase of its growth plan, what the right capital structure is, how to finance a potential acquisition — without the benefit of a financially trained strategic partner at their side.

The Fractional CFO fills this gap. On their engagement days, they work with the CEO and leadership team on the long-range financial direction of the business: reviewing and challenging the three-year financial model, advising on capital allocation priorities, assessing the financial implications of strategic options under consideration, and ensuring the business has the financial infrastructure and commercial rigour to support the growth strategy it is pursuing. Between engagement days, the Fractional CFO is typically available by phone or email for specific questions that require CFO-level input before the next scheduled visit.

Strategic financial planning at Fractional CFO level also includes scenario planning — producing clear financial models of what the business looks like under different operating scenarios — and risk management, ensuring the leadership team has a clear view of the financial risks the business faces and the mitigations available to it. The quality of this strategic finance input is often the most significant competitive advantage a growing business can develop, because decisions made with better financial analysis produce better outcomes than decisions made on intuition alone.

Investor and Lender Relationships

Managing the relationship with investors and lenders is a core CFO activity that most Financial Controllers are not equipped to handle — not because they lack the intelligence or the commitment, but because investor relationship management requires a specific combination of financial credibility, commercial confidence and experience of how investors think that is built through repeated exposure, not through finance qualification alone.

The Fractional CFO represents the business’s financial position to external stakeholders: presenting monthly or quarterly management reports to angel investors or VC portfolio teams, managing the relationship with a PE firm’s operating partner in businesses that have received PE investment, reporting to the board in formal and informal contexts, and managing bank relationships where a facility is in place. The credibility the Fractional CFO brings to these relationships — having managed similar relationships many times across their career — is often more valuable than the specific financial analysis they produce, because it signals to investors and lenders that the business has professional CFO-level financial oversight.

The Fractional CFO also prepares the business for investor interactions: coaching the CEO on how to present the financial story, reviewing the investor deck before it is presented, identifying the questions investors are likely to ask and ensuring the financial model can answer them, and helping the business develop the financial narrative that connects its operational performance to its strategic potential. Many founders and CEOs are not naturally comfortable in investor financial conversations; an experienced Fractional CFO who can prepare them thoroughly and participate alongside them in those conversations significantly improves the outcome.

Fundraising Support

For businesses preparing to raise external funding — equity or debt — the Fractional CFO typically leads the financial preparation of the fundraising. This is one of the highest-value applications of the Fractional CFO engagement, because fundraising is a time-limited, high-stakes process where the quality of the financial preparation directly affects the terms achieved and the speed of completion.

The Fractional CFO’s role in a fundraising typically includes: building the financial model and projections that form part of the investor pack, ensuring the model is logically structured, clearly assumption-driven and capable of withstanding the scrutiny of experienced investors; preparing the financial due diligence workpapers that the investor’s advisers will review; advising on the financial terms of the deal — the implied valuation, the terms of any equity instruments, the financial covenants in any debt facility; representing the business’s financial position to potential investors and their advisers in the due diligence process; and managing the financial workstream of the transaction to ensure it completes on time and on terms that serve the business’s interests.

A business that attempts to go through a fundraising process without CFO-level financial leadership will typically produce a financial case that is less convincing and a due diligence process that takes significantly longer than one led by an experienced Fractional CFO who has been through many similar processes. The cost of an underprepared fundraising — a lower valuation, worse terms, a longer process, or a deal that falls over in due diligence — almost always exceeds the cost of the Fractional CFO engagement that would have prevented it.

Oversight of the Finance Function

The Fractional CFO provides strategic oversight of the finance function and the team running it. Where the business has a Financial Controller or Finance Manager, the Fractional CFO manages them, sets quality standards for their output, reviews the management accounts and controls environment periodically, and ensures the quality and reliability of the financial information the business depends on.

This oversight function is particularly valuable in businesses where the operational finance team is capable at a transactional and management accounts level but lacks the senior judgement to identify systemic finance function weaknesses — a close timetable that is too slow, a control environment that has gaps, a chart of accounts that does not support the business’s reporting requirements, or an accounting system that is no longer adequate for the business’s size and complexity. The Fractional CFO’s periodic review of the finance function identifies these issues before they create material problems and drives the improvements that keep the function fit for purpose as the business grows.

The Fractional CFO also provides development support to the in-house finance team. A Financial Controller or Finance Manager who has access to a Fractional CFO as a senior finance mentor typically develops faster than one who is operating without senior guidance. The Fractional CFO can review the management accounts pack with the FC and provide structured feedback; help the Finance Manager prepare for a difficult conversation with a bank or a commercial counterparty; and provide guidance on complex accounting judgements that the FC would otherwise need to seek from an external accountant at significant cost. This development value is a secondary benefit of the Fractional CFO engagement that is rarely quantified but is real and lasting.

Who Typically Engages a Fractional CFO?

The Fractional CFO model is most commonly used in four types of business situation. Understanding which one applies helps businesses determine whether a Fractional CFO is the right solution and what the engagement should involve.

Early-stage growth businesses (£3m–£20m revenue). A business that has a Finance Manager or Financial Controller managing the operational finance function but lacks the board-level strategic finance leadership to support its next phase of growth is the classic Fractional CFO client. The CEO is making the business’s most important financial decisions without a financially trained strategic partner, and the finance function — however competent at month-end and compliance — is not providing the commercial financial analysis the business needs to make better decisions. A Fractional CFO working one to two days per week provides that missing strategic dimension at a fraction of the cost of a full-time CFO appointment.

Businesses preparing to raise external funding. A seed or Series A fundraising, a PE growth equity investment, or a bank debt facility all require CFO-level financial preparation and investor relationship management. Many businesses at this stage do not have a full-time CFO but need one for the six to twelve months of the fundraising process. A Fractional CFO engaged specifically for the fundraising period provides the required CFO credibility and experience without the commitment of a permanent appointment that may not be warranted once the funding round is complete.

PE-backed businesses post-investment, pre-permanent CFO. The PE investor typically requires CFO-level reporting and relationship management from day one of investment. If the business does not have a full-time CFO, a Fractional CFO covers this requirement while the permanent search runs — which typically takes six to sixteen weeks depending on the seniority of the role and the complexity of the PE-backed environment. This bridging role is one of the most common Fractional CFO scenarios that Accountancy Capital places.

Established businesses with periodic CFO needs. A business that has concluded its ongoing strategic finance needs can be adequately served by a Fractional CFO working one day per week — supplemented by a strong FC managing the operational finance function — uses the Fractional CFO model as a permanent structural choice rather than a transitional arrangement. This is common in stable, profitable businesses where the finance function runs well and the strategic finance demands are episodic rather than continuous. Monthly board meetings, annual banking renewals, periodic strategic reviews — these are the situations where the Fractional CFO adds the most value, and a one-day-per-week engagement can cover them comfortably.

What a Fractional CFO Is Not

Not a Fractional Financial Controller. The FC role is operational — the FC owns month-end, financial controls, audit, compliance and the finance team. The Fractional CFO is strategic — they focus on investor relationships, capital structure, long-range financial planning and board-level finance leadership. Many businesses that believe they need a Fractional CFO actually need a Fractional FC alongside an existing Finance Manager; understanding which one the business genuinely needs prevents a significant misalignment between the engagement and the actual need. See the Fractional Financial Controller page for the distinction.

Not a financial consultant. A consultant is engaged for a specific project with a defined deliverable and a defined end date. The Fractional CFO has an ongoing, relationship-based engagement with the business — attending board meetings, managing investor relationships, working with the CEO on strategic financial decisions — rather than delivering a one-time output and disengaging. The ongoing nature of the relationship is what allows the Fractional CFO to provide the contextual depth and continuity that a one-off consultant engagement cannot replicate.

Not available outside their engagement days. The Fractional CFO works a defined number of days per month. On the days they are not engaged with your business, they are engaged with their other clients. For straightforward questions, most Fractional CFOs will respond by email or phone between sessions — but for time-sensitive situations requiring immediate CFO-level attention, the fractional model has a structural limitation. Businesses going through a live transaction, a financial crisis, or a period of intensive investor engagement may find that a full-time interim CFO or a significantly increased fractional commitment is required for the duration of that intensive period.

Not an alternative to the FC or FM. The Fractional CFO does not replace the Financial Controller or Finance Manager — they work above and alongside them. A Fractional CFO without a capable FC or FM beneath them will spend their engagement days doing operational finance work rather than strategic finance work, which defeats the purpose of the engagement. The model works best when the operational finance function is in capable hands and the Fractional CFO can focus on the strategic dimension that the FC or FM cannot provide.

How to Structure a Fractional CFO Engagement

A Fractional CFO engagement is typically structured on a monthly retainer basis. The retainer specifies the number of engagement days per month, the core activities the Fractional CFO will cover during those days, the reporting line (the Fractional CFO typically reports directly to the CEO), and the notice period if either party wishes to change the arrangement.

Most Fractional CFO engagements run at between one and two days per week — four to eight days per month. At one day per week, the Fractional CFO is able to attend the monthly board meeting or management meeting, review the management accounts, and have a substantive strategic conversation with the CEO. At two days per week, the engagement is sufficient to lead a budget process, manage an active investor reporting cycle, or support a fundraising alongside the existing operational responsibilities.

The most effective Fractional CFO engagements have a clear rhythm: defined engagement days with a predictable schedule, a clear set of deliverables for each visit, regular catch-ups between sessions for time-sensitive matters, and a quarterly or annual review of the engagement scope to assess whether the level of commitment remains appropriate as the business evolves. Where the engagement lacks this structure — where the Fractional CFO is reactive rather than proactive, responding to requests rather than driving a defined programme of work — the value delivered is typically lower than the potential of the model.

The Cost of a Fractional CFO

Fractional CFO engagements are typically structured on a monthly retainer basis, priced per day at a rate that reflects the CFO’s experience level and the nature of the engagement. In London, experienced Fractional CFOs with a track record of PE-backed or growth-stage business experience typically charge £1,000–£1,500 per day. At two days per week — eight days per month — this represents a monthly cost of approximately £8,000–£12,000, or £96,000–£144,000 per year.

The comparison with a full-time CFO makes the financial case for the fractional model clear for businesses in the £5m–£30m range. A full-time CFO at the experience level required for a sophisticated PE-backed or growth business costs £190,000–£260,000 per year in total employment cost including salary, bonus, employer NI, pension and benefits. A Fractional CFO at two days per week delivers CFO-level strategic input at £108,000–£162,000 per year — without the employment obligations, the notice period risk, or the recruitment fee. For businesses where two days per week of CFO-level input is sufficient, the fractional model consistently delivers better value than the permanent alternative. The Fractional CFO recruitment page covers the typical structure and sourcing of these engagements in more detail.

The IR35 Question for Fractional CFO Engagements

Most Fractional CFO engagements are structured as personal service company arrangements — the Fractional CFO invoices through their limited company rather than being employed directly. Under the off-payroll working rules (IR35), the business engaging the Fractional CFO is required to assess whether the engagement is effectively one of employment for tax purposes, and if it is, to deduct PAYE and employer National Insurance from the payments made.

The key factors in the IR35 assessment for a Fractional CFO engagement are: control (does the business control how the work is done as well as what is done?), substitution (could the Fractional CFO send someone else to fulfil the engagement?), and mutuality of obligation (is there an ongoing obligation to provide and accept work?). A Fractional CFO working across multiple clients, with the flexibility to decline specific assignments and the ability to sub-contract, is more likely to fall outside IR35 than one who works exclusively for one business on a fixed schedule and follows the business’s instructions on how to work. The HMRC off-payroll working guidance and the CEST tool should be used to make a formal determination at the outset of each engagement.

Further Reading

• ICAEW: Finance Function Leadership — guidance on the CFO role and the structure of the finance function it leads.
• HMRC: Off-Payroll Working (IR35) — the employment status framework relevant to Fractional CFO engagements.
• Companies Act 2006: Directors’ Duties — relevant where the Fractional CFO is also appointed as a statutory director of the company.
• CIMA: Finance Transformation — research on how the CFO role delivers strategic value and how it has evolved in response to changing business needs.
• HMRC: Check Employment Status for Tax (CEST) — the tool for making an IR35 determination at the start of a Fractional CFO engagement.