A growing business needs CFO-level capability when financial decisions start to outpace the experience of the people making them. In practice this happens between £2m and £8m of revenue, when the owner is being asked to underwrite decisions on funding, structure or acquisition that were not part of the original plan. The right CFO arrangement at that stage is rarely full-time and rarely permanent.
In this article
- What does a CFO actually do that a finance manager does not?
- What are the typical thresholds at which a business needs a CFO?
- Fractional CFO, interim CFO or full-time hire, which fits?
- How do you justify the cost of a CFO before you have one?
- What signs tell you you have left it too late?
- What should a new CFO change in the first 90 days?
What does a CFO actually do that a finance manager does not?
A CFO turns financial information into commercial decisions. A finance manager keeps the books. The distinction is not about seniority, it is about the question the role exists to answer. A finance manager is asked: are the numbers right? A CFO is asked: should we do this, and if so on what terms?
That difference shows up in three places. The first is in deal evaluation: a CFO can sit opposite a vendor or a funder and assess what they are actually offering, then negotiate the terms. The second is in capital structure: a CFO decides how the business should be funded, what mix of debt and equity is appropriate at each stage, and which lenders are worth approaching. The third is in board-level reporting: a CFO produces information that supports decisions, not just compliance.
In practice, most owner-managed businesses confuse the two roles for years, often because they have an excellent finance manager and assume that is enough. It usually is not, but the gap is invisible until a decision is needed that the finance manager cannot reasonably make.
What are the typical thresholds at which a business needs a CFO?
Three thresholds matter, and they apply in any sector. The first is revenue: between £2m and £8m, the volume of financial decisions overtakes the owner's bandwidth and a part-time CFO becomes economic. The second is complexity: a multi-entity group, regulated activity, or property portfolio creates its own pressure regardless of revenue. The third is event-driven: an upcoming refinancing, acquisition, exit or major capital project usually exposes the gap immediately.
The lazy version of this advice is to pick a revenue number. The honest version is that revenue is a proxy for the other two. A £4m care home group with three SPVs and a development pipeline needs CFO capability before a £20m single-site distributor does. A property group considering its first £5m refinance will discover the gap on the day the term sheet arrives.
If you are in the £2m-£8m revenue range, ask whether you have made a decision in the last 12 months that you would have made differently with better financial input. Most owners who think about it find at least one.
Fractional CFO, interim CFO or full-time hire, which fits?
For owner-managed businesses below £15m revenue, fractional is almost always the right starting point. A fractional CFO works one or two days a week against a defined remit, costs a fraction of a full-time hire, and gives the business board-level finance capability without committing to it permanently. Most fractional engagements run for 12 to 36 months before transitioning to a full-time hire or being phased out.
Interim is different. Interim CFOs cover a defined gap such as a parental leave, a sudden departure, or a specific project (a refinancing, a sale process). Day rates are higher than fractional but the engagement is bounded. Interim is for known events, fractional is for ongoing capability.
Full-time CFOs make sense when the business has crossed roughly £15m revenue, has a finance team of five or more, and is dealing with continuous funding, M&A, or regulatory complexity. Below that, a full-time CFO is usually under-utilised and the business is paying for capability it cannot consume.
How do you justify the cost of a CFO before you have one?
Frame it as the cost of decisions made without one. A typical fractional CFO engagement runs £40k-£90k a year. A single tax-structuring decision avoided, a single funding round on better terms, or a single acquisition where the price was renegotiated by 5% will usually cover that cost in year one. Owner-managed businesses regularly leave six-figure sums on the table by underwriting financial decisions without senior input. The issue is that the money lost is invisible, there is no line in the management accounts called "decisions made worse than they could have been."
According to a 2025 survey by ICAEW of mid-market UK businesses, 41% of owner-managers said they had subsequently regretted at least one major financial decision taken without independent advice in the previous three years. The most common categories were under-pricing on exit, over-paying on acquisition, and accepting funding terms that proved restrictive.
What signs tell you you have left it too late?
Five recurring signs indicate the gap has become material. Cash forecasts are produced but not actually used to drive decisions. Funding conversations are taken on the funder's terms because there is no internal capacity to push back. Acquisitions are pursued without independent valuation. Tax structures are inherited rather than designed. The owner is making board-level financial decisions on the train home from a customer meeting.
None of these is fatal in isolation. Together, they describe a business that has outgrown its finance function and is paying for it through worse decisions. The cost is rarely a single event. It is a slow accumulation of small commercial losses that eventually becomes obvious in retrospect.
What should a new CFO change in the first 90 days?
A good fractional CFO produces three things in the first 90 days. A clear view of where the business actually makes its money, usually a surprise to the owner. A 13-week rolling cash flow tied to commitments, not aspirations. And a short list of the two or three financial decisions in the next 18 months that will most determine the next phase of the business.
What does not happen in 90 days is wholesale change. The right CFO spends the first quarter understanding the business and earning credibility with the existing team, then drives change from a position of authority. Anyone who comes in and rebuilds the finance function in week two is solving the wrong problem.
Written by Bharat Varsani FCCA. Director of Key Ledgers Global, currently operating at CFO level within a 15-entity care and property group with £55m+ revenue and £205m of assets under active CFO management. CPR Part 35 Forensic Expert Witness and former auditor with 20+ years across owner-managed groups.
Sources: ICAEW 2025 Mid-Market Business Confidence Monitor for the cited 41% figure; the Recruitment & Employment Confederation 2025 Salary Guide for fractional CFO market rates.
Frequently asked questions
What is the difference between a CFO and a finance director?
In the UK the titles are largely interchangeable. Both are board-level finance roles. CFO tends to be used by businesses with international, PE-backed or US-influenced reporting structures; FD is the more traditional UK term. The actual remit depends on the business, not the title.
How much does a fractional CFO cost in the UK?
Day rates for an experienced UK fractional CFO typically run £900 to £1,800 depending on sector and remit. Most engagements settle at one or two days a week, giving an annual cost of £40k to £90k for ongoing capability that would cost £150k+ as a full-time hire.
Can a fractional CFO sit on the board?
Yes. Many fractional CFOs are appointed as statutory directors or attend board meetings as advisers. The decision turns on whether the role needs decision-making authority or whether observer status is sufficient. Board appointment also affects insurance, indemnity and personal liability.