The short answer
At least five labels circulate for external CFO capability. Behind them sit only two models:
- Ongoing financial leadership, part-time. Fractional CFO, outsourced CFO, part-time CFO and CFO as a Service all mean essentially this.
- Filling a role on a fixed term, usually full-time. That is interim management, often as an interim CFO.
The dividing line runs not between the labels but between ongoing and partial on one side and fixed-term and whole on the other. Sort that out and offers become comparable; before that, they are not.
Fractional or interim CFO for a scale-up with investors?
For VC- or PE-backed scale-ups, the trigger matters more than the label. Rule of thumb: if a fixed deadline with a heavy workload is coming up – a vacancy, a funding round, a due diligence, an exit – an interim CFO fits. If finance leadership is needed on an ongoing basis but not full time, a fractional CFO fits.
| Trigger | Best-fit model | Why |
|---|---|---|
| CFO resigns or drops out | Interim CFO | The role has to be fully covered at once; board reporting and cash management continue. |
| Funding round in three to six months | Interim CFO, then fractional CFO | Financial plan, data room and investor meetings take several days a week. |
| Exit or financial due diligence | Interim CFO | Fixed timeline, heavy workload, clear end date. |
| Add-on integration after an acquisition | Interim (CFO or finance manager) | A time-limited project with a defined finish. |
| Monthly investor reporting and planning without an in-house CFO | Fractional CFO | Ongoing need, but not full time. |
| Sparring for founders before board meetings | Fractional CFO | A few days a month are enough. |
In practice, many scale-ups switch between the two: interim through the round or the exit, then fractional for day-to-day operations until an in-house role pays off. nugrow offers both – as an interim CFO or a fractional CFO – so the switch between models works without changing provider. Day rates are on the pricing page.
The terms at a glance
| Term | Origin | Model it means | Where it mostly appears |
|---|---|---|---|
| Fractional CFO | US usage, literally a “fractional” CFO | Ongoing part-time | Startup and VC circles, English-speaking providers |
| Outsourced / external CFO | General business usage | Ongoing part-time | Mid-market, classic consulting |
| Part-time CFO | Plain description | Ongoing part-time | Less common, but the most precise |
| CFO as a Service | Borrowed from software vocabulary | Ongoing part-time, usually modular | Providers that switch individual services on and off |
| Interim CFO | Established, defined by industry associations | Fixed-term, usually full-time | Providers, associations, corporate groups |
Occasionally virtual CFO, CFO on demand or the German CFO auf Zeit join in. They add nothing.
The proliferation is not accidental: a new label makes a familiar offering look new. For buyers it mostly means friction – four enquiries to four providers, four different words for the same service, and four proposals that cannot be laid side by side.
The one dividing line that matters
| Question | Ongoing part-time | Interim |
|---|---|---|
| Trigger | The function is needed, but not full-time | A role is vacant or a specific project is due |
| Time commitment | A few days a month up to several days a week | Mostly full-time or close to it |
| Duration | Ongoing, scope adjustable | Fixed term; via providers 7.1 months on average |
| Billing | Day rate and agreed workload | Day rate |
| End | Open, with a notice period | Defined from the outset |
| Contract question | Usually uncritical, because there is no integration | Critical when purely bridging a vacancy |
The last row is the one that gets overlooked and costs the most. Bridging a regular position one-to-one sits closer to German temporary staffing law than a proposal quoting a day rate suggests – with consequences that fall mainly on the client company. The detail is in the piece on contract forms and bogus self-employment.
What the two models cost
| Model | Billing | Cost reference (provider-specific) |
|---|---|---|
| Fractional / outsourced CFO / CFO as a Service | Day rate and agreed workload | At nugrow: from EUR 1,800/day excluding VAT × agreed days |
| Interim CFO, head of finance | Day rate | €1,400–2,500 per day |
| Interim CFO in restructuring or a corporate group | Day rate | from €3,000 per day |
| Permanent hire | Fully loaded annual cost | €140,000–300,000 per year |
Within the retainer, the range moves with scope: a few days a month for sparring and reporting review at the lower end, two to three days a week with de facto financial leadership at the upper. On interim assignments, going through a provider typically adds 25 to 35 percent to the day rate.
Compare the same period and the workload actually required. Include employer costs, recruitment and vacancy costs for a permanent hire. There is no fixed break-even threshold; an in-house role is especially relevant when there is sustained workload and the role can be filled. Further reading: interim management in the finance department.
How to spot a relabelled offering
The term is everywhere, the model nowhere. If a page says “fractional CFO” ten times but never how many days a month that means, the actual information is missing.
Unclear pricing. Ask for the day rate, planned workload, deliverables, additional expenses and rules for changing the scope. A transparent proposal makes the options comparable.
Interim and part-time are blurred together. Selling both as the same thing means either the model has not been thought through or the contract question is being pushed onto the client.
Nothing is said about the end. Ongoing part-time work needs a notice period and adjustable scope in the proposal; interim needs a defined end and a handover.
The scope stays a list. “Controlling, reporting, planning” is a heading. What is delivered monthly and what is billed on top is the answer.
Which term is useful when
For your own search, choose the word your counterpart uses. In startup and investor circles fractional CFO lands well; in the German mid-market externer CFO is understood immediately while the English term invites questions. CFO as a Service signals that services are modular. Reserve interim CFO for cases where a genuinely fixed-term appointment is meant – otherwise you get day-rate proposals for a job that is not one.
For a tender the label matters least. What counts: which outcomes have to exist after 90 days, how many days a month are budgeted for them, and whether the arrangement is meant to be ongoing or fixed-term. With those three, proposals become comparable regardless of the word on the cover page.
Frequently asked questions
What is a fractional CFO?
An experienced finance leader who works for a company on an ongoing but partial basis – typically a few days a month up to several days a week. The term comes from the US market; outsourced CFO, part-time CFO and CFO as a Service describe essentially the same model.
What is the difference between a fractional CFO and an interim CFO?
A fractional CFO provides ongoing part-time finance leadership with adjustable scope. An interim CFO takes responsibility for a defined period, for example during a vacancy or a special project. At nugrow, both are budgeted using the agreed day rate and workload; duration, scope and notice period are contractual.
Fractional or interim CFO – which fits a scale-up with investors?
It depends on the trigger. For a vacancy, a funding round, a due diligence or an exit, an interim CFO fits because a lot of capacity is needed for a limited time. For ongoing investor reporting, planning and board preparation without a full-time need, a fractional CFO fits. Many scale-ups combine both: interim through the round or the exit, then fractional for day-to-day operations.
What does a fractional CFO cost in Germany?
CFO support at nugrow starts at EUR 1,800 per day, excluding VAT. The budget is the agreed day rate multiplied by the agreed workload. Eight days, for example, cost EUR 14,400 excluding VAT; this is a worked example, not a monthly package.
Is an outsourced CFO the same as CFO as a Service?
In effect, yes. “CFO as a Service” additionally emphasises that the offering is modular – accounting, reporting, planning, liquidity and investor communication can be switched on and off individually. The underlying model in both cases is ongoing financial leadership, part-time.
When does a permanent CFO position make more sense?
Compare the same period and the workload actually required. Include employer costs, recruitment and vacancy costs for a permanent hire. There is no fixed break-even threshold; an in-house role is especially relevant when there is sustained workload and the role can be filled.
Which term should I use in my enquiry?
The one your counterpart understands – fractional CFO in startup circles, externer CFO in the German mid-market. More important than the word are three data points: which outcomes have to exist after 90 days, how many days a month are budgeted, and whether the arrangement is ongoing or fixed-term.
Further reading
- Interim management in the finance department – roles, how an assignment runs and the first 90 days.
- Interim CFO contracts in Germany – service contract, temporary staffing and bogus self-employment.
- How to find an interim CFO – the four routes to a provider and twelve selection criteria.
- CFO as a Service at nugrow – how the modules are tailored to individual companies.
Sources
fully loaded cost of a permanent hire: MRH Beratung. Day-rate ranges by role and provider margin: Interim Profis and Effizienzbuchhalter. Average day rate and assignment length: DDIM market study 2026. CFO median salary: StepStone salary data Germany. All figures as of 2026; they describe the market, not the terms of any individual provider.
