Most founders ask this question too late. By the time the need is obvious — a fundraise stalling because the financial model isn't credible, an investor asking for reporting that doesn't exist, a board meeting where no one can explain the variance — the damage is already being done.
The better question is not "when do I need a CFO?" but "what financial decisions am I making right now, and am I making them well?" The answer to that usually tells you whether you need one already.
This article sets out a practical framework: what to look for at each stage, the signals that indicate you've waited too long, and how to think about the build vs. buy decision when it comes to senior finance capability.
The revenue threshold is a distraction
There is a persistent myth that startups need a CFO at a specific revenue milestone — commonly cited as £1M, £5M, or £10M ARR. The number varies depending on who is giving the advice, but the framing is wrong.
Revenue is a proxy for complexity, not a direct measure of it. A £2M ARR SaaS business with PE backing, multi-currency operations, and a fundraise on the horizon has far more financial complexity than a £10M ARR professional services firm with a single entity, domestic clients, and stable ownership. The first business almost certainly needs a senior CFO. The second might be fine with a good Finance Director and a part-time accountant.
The right question: Is the gap between the financial decisions you need to make and the quality of financial information available to support them getting wider or narrower? If it is getting wider — regardless of your revenue — you need a CFO.
What drives the need: the three pressure points
In practice, the need for a CFO is driven by one or more of three things — investor pressure, operational complexity, and founder bandwidth. Understanding which one is driving the need shapes what kind of CFO support is most appropriate.
Investor pressure
The moment institutional capital enters the picture — or is about to — the financial requirements of the business change materially. PE and VC investors expect board packs that are structured, timely, and comparable period-on-period. They expect management accounts that reconcile to statutory accounts. They expect a financial model that is live, updated, and used in decision-making — not produced for fundraising purposes and then filed away.
If you are preparing to raise institutional capital, or if you have already raised it and are now trying to meet the reporting expectations that came with it, you need a senior finance person. The question is how senior and whether they need to be full-time.
Operational complexity
Single entity, single currency, domestic customers — these businesses can usually be managed with a good accountant and a reasonable finance system. Add a second entity, a second currency, an international team, or a revenue model with meaningful complexity (subscriptions, milestone-based contracts, multi-year deals with variable recognition) and the accounting, reporting, and compliance requirements multiply rapidly.
Cross-border operations in particular are underestimated. Transfer pricing, local statutory reporting obligations, multi-entity consolidation, and the varying regulatory environments across the UK, EU, US, and APAC require expertise that most accountants and bookkeepers do not have.
Founder bandwidth
This is the most common trigger in practice, and also the one most often ignored for longest. When the founder is the de facto CFO — signing off management accounts, managing the accountant, building the financial model, fielding investor financial questions — there is an opportunity cost that rarely appears on any dashboard.
The cost is not just the time spent on finance tasks. It is the quality of the financial decision-making — because a founder doing five jobs simultaneously does not have the bandwidth to do the finance job properly, even if they have the capability to do it well.
The six signals you have waited too long
These are the patterns that tend to appear in the period just before a business engages a fractional CFO. Most businesses will recognise at least two or three. If you recognise four or more, the case is urgent.
Board meetings run on intuition
Revenue is discussed but not disaggregated. Cash is monitored but not forecasted. Variances are reported but not explained. The numbers are present — the insight is not.
The fundraise is 6 months away
Serious investors will scrutinise the model, the assumptions, the cap table, and the data room. Preparing for that without senior financial support is a significant risk — to both outcome and timeline.
The CEO owns finance
When the founder is signing off on management accounts, chasing management information, and fielding investor questions — the business is underinvested in its finance function.
Multi-jurisdiction operations
Cross-border compliance, transfer pricing, multi-currency consolidation, and multi-entity group structures require expertise a local bookkeeper or part-time accountant cannot provide.
Exit or M&A on the horizon
Financial due diligence is where deals are delayed and price is chipped. Getting the business financially clean — accounts, contracts, liabilities, earn-out structures — is CFO work, done well in advance.
Growth outpacing reporting
Headcount has scaled, product lines have expanded, but the reporting has not kept pace. Decisions are being made on stale or incomplete information — and the gap is widening.
CFO capability by stage: what you need and when
Rather than a single threshold, it is more useful to think about what financial capability is appropriate at each stage of growth — and how to close any gap between what you have and what you need.
Full-time hire vs fractional CFO: the build vs. buy decision
Once the need is established, the next question is how to address it. The case for a fractional CFO is strongest when one or more of the following applies:
- The need is strategic, not operational. If what you need is someone to build the financial model, own the board relationship, and lead the next fundraise — that is CFO work, not FC work. And it does not require five days a week. A fractional CFO at 6–8 days per month can deliver that without the overhead of a full-time hire.
- The timing is uncertain. If you are 9–12 months from closing a round, and you need serious financial leadership in place for the process but do not want to commit to a permanent hire before the capital is in the bank — a fractional arrangement bridges that gap cleanly.
- You have not yet built the finance function. Hiring a full-time CFO into a business with no Finance Manager, no management accountant, and no systems is setting them up to spend their time on operational firefighting rather than strategic work. A fractional CFO can build the infrastructure first, so that when the full-time hire comes in, they can operate at the right level from day one.
- You need cross-border expertise now. Senior CFOs with direct experience across multiple jurisdictions are expensive to hire full-time and hard to find. Access that expertise fractionally, at the point when you need it, rather than embedding a full-time cost structure for a capability that may only be needed for 18 months.
On cost: A senior fractional CFO at 6 days per month in the UK typically costs £9,000–£24,000 per month, depending on experience. A comparable full-time CFO hire — salary, employer NI, pension, benefits, and opportunity cost of recruitment — runs to £200,000–£350,000+ per year. For most businesses between £1M and £15M ARR, the fractional model is both more cost-effective and more flexible.
The question is not which is cheaper. It is which gives you the right capability at the right cost, at your current stage — and a fractional engagement answered that question for the majority of growth companies.
The cost of waiting
The opportunity cost of not having a CFO is rarely calculated. It appears in decisions made without adequate financial analysis, in fundraising processes that take longer or close at lower valuations than they should, in cash crises that could have been anticipated, in compliance failures that trigger regulatory cost, and in the time a founder spends on finance rather than the business.
None of these show up on a P&L. But they are real costs — often significant ones.
The decision to bring in senior financial leadership is rarely made too early. It is almost always made too late. The businesses that move quickly tend to be better prepared, better funded, and better positioned for exit than those that wait for the pressure to become undeniable.
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