When Does a Business Need a Fractional CFO?

The fractional CFO has become one of the most common senior finance engagement models in the UK. It combines the strategic leadership of a full-time Chief Financial Officer with the cost of a part-time arrangement, typically one or two days a week on a monthly retainer, which suits a business that needs board-level financial thinking but cannot yet justify a permanent CFO.

But the model is not right for every business at every stage. A fractional CFO works very well in some situations and delivers much less in others, and in a good number of cases the real need is not a CFO at all but a qualified Financial Controller who can get the numbers right first. This guide sets out which situations suit the fractional CFO model, which do not, what it typically costs, and how to tell whether a fractional Financial Controller is the better place to start. For a shorter description of the role itself, see what does a fractional CFO do?

What a fractional CFO actually provides

A fractional CFO provides one or two days a week of senior financial leadership. In London, day rates typically run from £750 to £1,300 depending on experience and complexity, which puts a one-day-a-week engagement at around £39,000–£66,000 a year and a two-day engagement at around £78,000–£132,000. For that, the business gets:

• a qualified, experienced CFO-level professional who understands capital structure, investor relationships, financial modelling and strategic planning;
• availability for board meetings, investor and lender meetings, and significant commercial decisions; and
• the ability to leave day-to-day operational finance with a Financial Controller or Finance Manager while the CFO concentrates on the strategic and investor-facing work.

What a fractional CFO does not provide is full-time availability. On the days they are not with your business they are working for other clients, and they are not reachable on demand. They cannot manage a month-end crisis, a sudden regulatory issue or a covenant breach with the speed and attention of a full-time CFO. Businesses that need their CFO present every day, because the financial complexity, pace of change or investor relationship demands it, should be looking at a permanent or interim CFO rather than a fractional one.

The business stages that best suit a fractional CFO

Pre-seed to seed: first financial credibility

A business with a proven concept, an early revenue model and an investor pitch to prepare needs a level of financial credibility that a founder with a spreadsheet cannot provide alone. At this stage the fractional CFO builds the financial model behind the investment case, prepares the investor pack, attends investor meetings as the financial voice of the business, and makes sure the due diligence that follows does not uncover weaknesses that undermine the terms.

Engagements here are usually one day a week or less, sometimes on a defined project basis rather than an open retainer. A one-day London retainer typically runs at around £3,250–£5,500 a month. The return is a stronger investment case and a smoother due diligence process.

Series A and growth: between rounds

The period between rounds, after a Series A closes and before the Series B pitch, is where the fractional model most often gives the best balance of cost and value. The business now has institutional investors who expect monthly reporting, quarterly board packs and a senior finance voice between meetings. But it is not yet large or complex enough to justify a permanent CFO on a base salary of around £130,000–£215,000 while it is also investing heavily in product, engineering and sales.

The fractional CFO at this stage owns the investor pack, attends the board, manages the lead investor relationship between meetings, and provides the modelling behind major decisions such as pricing changes, new markets and significant hires. Engagements are typically up to two days a week, around £6,500–£11,000 a month in London. That buys the most valuable part of a CFO’s contribution, the investor relationship, the modelling and the board-level judgement, while a Financial Controller or Finance Manager owns the operational finance. Our guide to building an investor-ready reporting pack covers what investors expect to see each month.

PE-backed at investment: interim or fractional?

When a private equity fund invests, its reporting expectations usually require more from the finance function than the business has needed before: a shorter close, more detailed investor reporting, covenant monitoring and transaction support. Whether the answer is a fractional CFO or a full-time CFO, permanent or interim, depends on the scale of the business, the fund’s reporting requirements and the strength of the existing finance team. The British Private Equity & Venture Capital Association publishes useful material on what investors expect of portfolio companies.

For PE-backed businesses of roughly £5m–£15m revenue with an experienced Financial Controller already in post, a fractional CFO providing the investor-facing leadership while the FC runs the finance function is often the right model. Above about £15m revenue, or with an active acquisition programme or a complex capital structure, the demands on the CFO usually exceed what a fractional arrangement can deliver, and a full-time appointment is more appropriate. Where the gap is really at controller level, see our guide to the fractional FC for PE-backed businesses.

Founder-led business approaching its first external investor

A founder-led business that has run its finances with a bookkeeper, an external accountant and the founder’s own oversight, and is now approaching an angel round, an EIS raise or its first institutional investment, is one of the most consistent use cases. The investor expects a financial model, a finance function ready for due diligence and a credible senior finance presence in the room.

The fractional CFO here is typically engaged for three to six months around the investment process, from model build through investor meetings to completion, and may continue on a reduced retainer afterwards to handle the reporting the new shareholders require. Our guide to the Financial Controller’s role in fundraising due diligence explains how the work splits between the CFO and the controller during a raise.

When the fractional CFO model does not work

The model is consistently unsuitable in four situations.

Financial stress. A covenant breach, a strained banking relationship or a cash crisis needs full-time leadership to manage the bank, restructuring advisers and creditors. An interim CFO is the right model, usually supported by a rigorous 13-week cash flow forecast.

A large or dispersed finance team. A team of eight or more, or one spread across several locations, is rarely manageable at two days a week. It needs more consistent presence than the fractional model provides.

Investors who expect daily access. Some hands-on PE investors find the fractional model unsatisfactory because the CFO is not available on their schedule. Before appointing, confirm explicitly with the lead investor that a fractional arrangement is acceptable.

Rapid commercial change. Where several new markets are being entered at once, an acquisition programme is running or a major product pivot is under way, the business needs daily financial input rather than periodic analysis.

When a fractional Financial Controller is the better first step

Many businesses that ask for a fractional CFO are really describing a controller-level problem: management accounts that arrive late or cannot be relied on, an unreconciled balance sheet, a difficult audit, weak controls or a bookkeeper who has been stretched beyond their role. A CFO cannot do strategic work on numbers that are not right, and a fractional CFO who spends their contracted days fixing the close is an expensive way of buying controller work.

A one-day fractional Financial Controller in London typically costs £29,000–£39,000 a year, against £39,000–£66,000 for a one-day fractional CFO, and fixes the underlying numbers that any CFO will later rely on. For many businesses of £2m–£10m revenue the sensible sequence is a fractional FC first, or a fractional Finance Manager where the need is lighter, with a fractional CFO added when a fundraise, a lender or an investor board arrives.

A fractional FC is usually the better first step when:

• the month-end close takes more than two or three weeks, or the management accounts are not trusted by the board;
• the balance sheet has not been properly reconciled, or the last audit produced significant adjustments;
• there is no fundraise, lender negotiation or investor board in the next six to twelve months; and
• the founder’s main frustration is information they cannot rely on, not strategy they cannot develop.

A fractional CFO is the better first step when there is a defined capital event ahead, when investors or lenders need a senior finance counterpart, or when the controller-level work is already in good hands. Our comparison of the Financial Controller and CFO roles sets out the difference in scope in more detail.

Comparing fractional, interim and permanent CFOs

The choice between a fractional, interim and permanent CFO comes down to three questions. How many days a week does the business genuinely need CFO-level leadership? Is the need time-limited or ongoing? And what can the business allocate to the CFO function each year? Our guide to interim versus fractional finance covers the same choice for roles below CFO level.

Interim day rates are similar to fractional rates, but because the interim works five days a week the monthly cost is far higher. Permanent benchmarks are covered in more depth in our CFO salary guide.

Fractional CFO day rate and cost benchmarks

Fractional CFO day rates in London typically range from £750 to £1,300, depending on the individual’s track record, the complexity of the engagement and the sector expertise required, with lower rates in the South East and the Midlands and North. Typical London retainers:

At two days a week the fractional model costs roughly half the all-in cost of a permanent CFO, and at three days it begins to overlap with the lower end of the permanent range. Businesses that genuinely need two or more days a week on an ongoing basis should compare the fractional cost carefully with the permanent alternative before defaulting to the fractional model. Our fractional CFO rates guide gives regional ranges and the full cost comparison, and our guide to finance team costs puts the CFO alongside the rest of the function.

Setting up a fractional CFO engagement for success

Before the CFO starts, confirm with your lead investor or fund that the fractional model is acceptable. Many accept it at earlier stages but expect a permanent CFO as the business grows; agreeing that up front avoids a disruptive change of course a few months in.

Define the contracted days, which days of the week the CFO works for you, and respect the boundary on other days. The most common cause of failure is a client who treats the fractional CFO as on call every day despite an agreed two-day arrangement. Clear days, with an agreed protocol for genuine emergencies, make the arrangement sustainable. Where the CFO works through their own company, IR35 status depends on the actual working arrangement; see HMRC’s guidance on off-payroll working.

What to include in a fractional CFO brief

A fractional CFO brief differs from an interim brief in one important respect: the key qualification is not only CFO capability but the ability to work well across a portfolio of clients. A brief that does not make clear the engagement is fractional attracts people between permanent roles as much as career fractional professionals.

A strong brief specifies:

• the number of contracted days a week, typically one or two;
• the expected duration, open-ended or with a defined initial period;
• the responsibilities in and out of scope, such as the investor pack, board meetings and modelling;
• the existing finance team and who the CFO will work alongside;
• any fundraising, transaction or investor event in the near term; and
• the monthly retainer budget or acceptable day rate range.

Stating the budget matters more in the fractional market than elsewhere. Career fractional CFOs know their market rate, and setting it correctly up front avoids a strong shortlist declining at the rate discussion.

The fractional CFO and the finance team

A fractional CFO works best when the team below is stable, capable and able to operate with some autonomy on the days the CFO is not there. The most important relationship is with the Financial Controller or Finance Manager who owns day-to-day finance: the person who runs the close, the bank and the team in the CFO’s absence.

Agree the authority boundaries explicitly: what the FC can approve alone, what needs the CFO’s input and how urgent issues are handled on other days.

Businesses with a strong FC in post get the most from a fractional CFO, because the CFO can spend their time on investors, planning and commercial analysis. Where the team below is thin, the CFO spends a disproportionate share of their days on operational issues, which erodes the value of the arrangement. That is often the point at which to strengthen the controller layer first; our guide to building a finance team around a Financial Controller covers how.

The move from fractional to permanent CFO

The fractional model is usually transitional. Most businesses that engage a fractional CFO expect to move to a permanent appointment when revenue justifies the full-time cost or the investor relationship demands full-time presence.

There are two routes. The first is to appoint the existing fractional CFO if they are interested and the relationship has worked. It is the smoothest transition, though portfolio and full-time executive skills do not always match. The second is to run a permanent search while the fractional CFO continues. That tests the full market but needs the handover managed carefully. Permanent CFO searches are covered on our CFO recruitment page.

How Accountancy Capital helps

Accountancy Capital is one of the five specialist firms of FD Capital Group. Our core focus is qualified finance below director level, so we place fractional Financial Controllers, Finance Managers and management accountants directly. Fractional CFO searches run with our sister firm FD Capital, which specialises in CFO and Finance Director appointments; see our fractional CFO recruitment page for how that works. If it is unclear which level you need, a consultant will recommend the role that fits.

We respond to every brief the same working day and typically present fractional candidates within days. Fees are agreed in writing before a search starts. Fractional CFOs and FCs we put forward are qualified through bodies such as the ICAEW, ACCA or CIMA.

Frequently asked questions

At what revenue does a business need a fractional CFO?

Revenue alone does not decide it. The trigger is usually a capital event, an investor board or a lender relationship. Many businesses of £2m–£10m revenue are better served by a fractional FC first, while PE-backed businesses of roughly £5m–£15m with a strong FC in post often suit a fractional CFO.

How much does a fractional CFO cost?

In London, typically £39,000–£66,000 a year for one day a week and £78,000–£132,000 for two, with day rates of £750–£1,300.

Can a fractional CFO replace a Financial Controller?

Not well. A fractional CFO relies on accurate numbers produced by someone else. Without an FC or Finance Manager running the close, the CFO’s days go on controller work at CFO rates.