Most people treat the interim CFO seat at a PE-backed business as a waiting room for the permanent job.
The data says that is a fantasy.
Research covered by CFO.com on Barton Partnership work puts the conversion rate from interim to permanent at PE-backed firms at roughly 36%. Only about four in ten interim finance chiefs even said they were open to staying under the right conditions. The rest are doing something else entirely: closing a capability gap, stabilising a reporting stack, carrying a business through diligence or exit, then moving on.
If you sit on an investment committee, that number should change how you hire. If you are the interim, it should change how you negotiate.
The job is not a try-before-you-buy
Sponsors still talk about interim CFOs as if the assignment is a six-month audition. Sometimes it is. More often it is a deliberate instrument:
- the deal thesis needs a finance leader who has already lived a similar hold period;
- the sitting FD cannot carry lender packs, board cadence and systems cleanup at once;
- management wants a grown-up in the room without locking a permanent package before the first 100 days are honest;
- exit is visible and nobody wants a brand-new permanent CFO learning the business in the CIM.
That is not a failed permanent search. That is a different product.
When boards blur the two, they get the worst of both: an interim who half-applies for the permanent seat, and a permanent hire who was never properly scoped.
Why conversion is low — and why that is often healthy
Low conversion is not automatically a governance failure. In PE it is frequently the design.
1. The skill that saves the hold is not always the skill that runs the next five years.
Rescue, refinance, ERP recovery, TP cleanup, warehouse go-live, carve-out — these are campaign sports. Steady-state FP&A leadership, culture and long-cycle talent development are different muscles. Pretending one person must be both is how you overpay for the wrong profile.
2. The best interims are expensive because they are liquid.
People who can land cold into a PE board pack and make it legible do not need your permanent role to feel successful. They need a clean mandate, decision rights, and a finish line. If your only retention tool is “maybe we will make it permanent,” you are bidding with monopoly money.
3. Sponsors already know who they might want long-term.
Often the permanent CFO is a known quantity from a prior portco, a portfolio talent map, or a search that was always going to conclude after the fire was out. The interim was never in that race. Telling them otherwise is theatre.
4. Conversion politics punish honesty.
If the interim is quietly campaigning for the seat, bad news arrives late. If the board pretends the door is open when it is not, trust collapses in month four. Clear “this is a closed-ended assignment” language is kinder and more commercial than soft ambiguity.
What good PE sponsors do instead
The high-functioning pattern is boring, which is why it works.
Name the product on day one. Stabilise / professionalise / exit-ready / systems rebuild / fundraise support. One primary job. Secondary jobs in writing, not in hallway vibes.
Separate the permanent search clock from the interim clock. If you might convert, say what evidence would justify it and when that decision will be taken. If you will not convert, say that before the first board. Ambiguity is not optionality. It is unmanaged risk.
Pay for outcomes, not for hope. Day rate or project fee against deliverables beats a discounted permanent package with a whispered upside. Interims who accept underpriced “try-outs” train sponsors to treat senior finance as a temp bench with equity cosplay.
Instrument the handoff. The value of a strong interim is not only the three months of packs. It is the operating system left behind: close calendar, board pack skeleton, cash bridge discipline, covenant early-warning, decision log, open diligence Q&A. If that does not exist at exit from the assignment, you rented a person. You did not buy capability.
What the interim should demand
From the other side of the table — and I sit there often enough — the commercial hygiene is simple.
Mandate in writing. What “done” looks like. What is out of scope. Who can overrule you. Which systems you own versus babysit.
Decision rights on cash and reporting. An interim CFO without authority over the cash bridge and the board pack is a commentator with a nicer title.
A clean conversion clause — or none. Either a dated decision gate with criteria, or an explicit non-conversion statement. Soft “we will see how it goes” is how both sides waste political capital.
Permission to build past yourself. If the assignment succeeds, the business should need you less at the end than at the start. That is the point. Hire the number two, fix the calendar, kill the heroics. Sponsors who punish that behaviour are selecting for dependency.
And get the tax wrapper right. A real PE interim is almost always outside IR35 when structured properly: own company, own tools, substitution/control reality, financial risk, and a finished assignment rather than a disguised employment. If the commercial deal is temporary employee with a day rate, you have already lost the product definition and invited a status fight you do not need. Sponsors who want interim outcomes should buy a genuine B2B assignment. Interims who want the economics of independence should not pretend they are on a probationary payroll.
Where AI changes the interim brief
This is no longer only a people story.
A modern interim CFO is often dropped into a business that still closes in Excel folklore while the sponsor deck claims “AI-enabled value creation.” The gap is becoming the job.
- Can the finance stack produce lender-grade cash visibility without a weekend of heroics?
- Are AI tools allowed to touch the close, the pack, the covenant model — and under whose control?
- Is “productivity” just headcount hope, or a measured reduction in cycle time and error rate?
I have written separately about measuring AI and local AI. The interim angle is blunter: if you only have 90–180 days, you cannot wait for a transformation theatre programme. You need a short list of automations that harden the close, the pack and the cash story before the next IC.
That is why conversion rates miss the point. The question is not “did we keep them?” The question is “is the business more finance-operable than when they arrived?”
The PE take
Interim CFO work at PE-backed companies is a professional service with a balance-sheet consequence, not a dating app for permanent hires.
Use it that way.
Hire for the campaign you are actually in. Pay for the outcome. Decide conversion on purpose, early, in writing. Measure success by the operating system left behind — not by whether the temp badge got upgraded.
And if you are the interim: stop auditioning for a role nobody agreed was open. Do the job that was bought. Leave the business harder to break than you found it.
That is the product. Everything else is soft focus.
Mark Hendy is a PE-facing interim CFO and founder of Tanous. Views his own. Conversion statistics referenced from public secondary reporting of Barton Partnership research via CFO.com; verify primary materials before relying on the figure in a live search process.
Sources / further reading:
CFO.com on interim-to-permanent conversion at PE-backed firms ·
Finatal interim finance insights ·
CFO optimism on AI impact ·
The CFO Who Can’t Measure AI ·
The CFO Case for Local AI









