When agencies hire a fractional CFO for the first time, most of the attention goes on qualifications and day rate. Both matter, but they miss the harder question: how do you tell a genuinely capable fractional CFO from someone who simply pitches well? We recently spoke with Stewart Mathieson, founder of Fractional Clients, whose agency has helped over 150 fractional executives build their client pipelines. His job is coaching fractional leaders on how to win work, which gives him an unusually clear view of what separates strong practitioners from weaker ones. That view is just as useful the other way round, for founders trying to work out who deserves a seat at their table before they hire a fractional CFO.
Why polish and capability are not the same thing
Mathieson splits fractional success into two distinct skills. The first is doing the work well and the second, running a business around that work. In his experience, plenty of technically strong fractional CFOs are poor at articulating their own value, while some of the smoothest pitches come from people whose delivery does not hold up once the engagement starts.
“There’s the being a good kind of employee, let’s call it, by actually driving value for the clients you’re working with, which is the biggest thing. But the other half is the entrepreneur side.” (Stewart Mathieson)
A confident pitch tells you someone can sell. It tells you nothing about whether they can do the job you’re hiring them for.
What to ask before you hire a fractional CFO
One of the more useful diagnostic questions Mathieson raised is about the source of a candidate’s client base. He argued that a healthy fractional practice should get most of its work through referrals rather than cold outreach, because referrals are evidence that past clients were satisfied enough to recommend them.
“If you can’t get over fifty percent of your work from referrals, then there’s probably something deeper there… maybe you’re just not providing enough value to your clients in general.” (Stewart Mathieson)
That gives founders a practical starting point, and the same discipline that applies to a due diligence checklist applies just as well to vetting the person you are about to trust with your numbers. Here are three questions to ask before you hire a fractional CFO:
What proportion of your current clients came through referral, and can I speak to one of them?
A candidate who hesitates here, or who cannot name a single client willing to be a reference, is worth treating with caution regardless of how strong their CV looks.
What did you actually deliver for your last two clients, in numbers?
Vague answers about improving financial visibility or strengthening controls are easy to say and hard to verify. A credible fractional CFO should be able to point to specific, measurable outcomes, such as a working capital improvement, a margin correction, or a successful funding round.
How do you structure engagements when a client relationship ends badly, and can you give an example?
Most experienced fractional CFOs will have encountered engagements that were more challenging or did not develop as expected. How they describe that experience, and whether they take any ownership of it, tells you more about their judgement than a list of successes ever will.
Why specialism matters when you hire a fractional CFO for agencies
Generalist finance advice rarely holds up against the specific pressures of agency economics, from utilisation and WIP to client-side billing cycles. Mathieson made the same point about the wider fractional market.
“No one wants to work with a jack of all trades, master of none… the more specialised the better.” (Stewart Mathieson)
A fractional CFO who has worked specifically with agencies should be able to speak fluently about margin pressure, resourcing, and cash flow timing without needing it explained to them. ICAEW’s own research on portfolio CFOs notes that most portfolio CFOs manage between three and ten clients at a time, which makes sector focus a practical necessity rather than a nice-to-have. If a candidate cannot point to agency-specific experience or comparable client work, that is worth probing before signing anything.
It is also worth noting how much easier it has become for anyone to sound credible on paper. AI tools now let outreach and pitch materials be personalised to a specific business in minutes, which is exactly the kind of work Mathieson’s own agency does for its fractional exec clients. A well-researched, individually tailored pitch is no longer a reliable signal of genuine expertise, since the same tools are available to everyone. Track record and referenceable client work matter more than they used to, not less.
ACC’s CFO Perspective
Strong presentation and genuine capability often diverge – you can talk the talk, but can you walk the walk? Our approach is to weight verifiable outcomes, referenceable clients, and sector-specific experience well above how confidently someone presents in a first meeting. A fractional CFO’s real value shows up in the numbers they leave behind, not the pitch that got them through the door.
One book worth your time
Mathieson recommended $100M Offers by Alex Hormozi, calling it one of the few genuinely practical books on building a compelling commercial offer. He said it shaped how his own agency positions its services to fractional executives, and that founders evaluating any professional services provider, fractional CFOs included, could benefit from understanding what makes an offer clear and easy to say yes to.
Getting the decision right
The decision to hire a fractional CFO is ultimately a judgement call about trust, not just credentials. The signals that matter most – referenceable client work, sector-specific experience, and a track record that holds up under questioning, – take a little longer to check than reading a polished bio. That extra diligence is usually what separates a genuinely good hire from an expensive mistake.
Frequently Asked Questions
What should I look for when I hire a fractional CFO?
Look beyond qualifications and day rate. Ask what proportion of their client base came through referral, request specific measurable outcomes from recent engagements, and check whether they have direct experience with businesses in your sector, such as agencies.
How do I know if a fractional CFO’s experience is genuine?
Ask for referenceable clients you can speak to directly, and request concrete examples of outcomes they have delivered, such as improved working capital or corrected margins, rather than general claims about experience.
Does a fractional CFO need agency-specific experience?
It helps considerably. Agency economics, including utilisation, WIP, and client billing cycles, differ from other sectors, so a fractional CFO with direct agency experience should already understand these pressures rather than needing them explained.
What is a reasonable referral rate for a fractional CFO to have?
Stewart Mathieson suggests that generating more than half of new work through referrals can be a useful indicator of client satisfaction. It shouldn’t be treated as a hard rule, but asking where a fractional CFO’s work comes from can reveal a lot about their track record.
ACC Finance Team
ACC Finance are a team of experienced CFOs and management accountants who combine executive financial leadership with practical commercial judgement to work closely with founders and leadership teams to strengthen margins, improve cash flow, and guide critical financial decisions.
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