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People3 min read2026-08-04

Fractional CFO: what one does, when to hire

What a fractional CFO actually does, roughly what one costs, and an honest test for whether your startup needs one yet or just needs its numbers in order.

A fractional CFO is an experienced finance executive who works for your company part time: a few days a month, on a retainer or contract, instead of a full-time salary. The pitch is compelling, CFO-level judgment at a fraction of CFO cost. Sometimes it is exactly what a startup needs. Often it is an expensive answer to a problem a founder could solve in an afternoon.

Here is the honest version of both halves.

What a fractional CFO actually does

The good ones do strategy, not bookkeeping. Typical scope:

  • Fundraising support. Building the model investors will interrogate, shaping the story, sitting in diligence calls.
  • Forecasting and scenario planning. What happens to cash if you hire three people, raise prices, or lose the big customer.
  • Board and investor reporting. Turning your numbers into the packet a board expects, every quarter, on time.
  • Pricing and unit economics. Margin analysis, pricing structure, cost of revenue.
  • Financial operations. Overseeing the bookkeeper and accountant you already have, so nothing falls between chairs.

Note what is not on the list: entering transactions, filing taxes, chasing invoices. That is bookkeeping and accounting. If someone sells you CFO hours to do bookkeeping, you are overpaying by a factor of five.

What a fractional CFO costs

ArrangementTypical cost
Hourly€150 to €350 per hour
Monthly retainer, light touch€2,000 to €5,000 per month
Monthly retainer, hands-on€5,000 to €12,000 per month
Full-time CFO, for comparison€12,000 to €20,000+ per month loaded

The wide ranges are real: price scales with the person's track record and how messy your finances are. The full market picture — publicly listed rates with named sources, what moves the price, and the sizing math — is in how much does a fractional CFO cost. A useful rule: a fractional CFO engagement costs about as much as a mid-level hire. Judge it with the same seriousness you would judge what any hire really costs.

The honest test: do you need one?

Ask what problem you are hiring for.

You probably need one when:

  • You are raising a priced round and the data room questions have gone past your depth
  • Revenue passed roughly €1M to €2M a year and decisions like pricing, hiring pace, and cash management now have real stakes
  • Your board expects reporting you do not know how to produce
  • Money moves in complicated ways: multiple entities, currencies, inventory, debt

You probably do not need one when:

  • You mostly want to know your runway, burn, and MRR. Those are arithmetic, not strategy. A runway model you keep current answers them for free, and that is precisely the job Plainhub does as you record what happens.
  • You want someone to "own the finances" because looking at them makes you anxious. A CFO cannot absorb that for you; the founder who avoids the numbers with a CFO becomes a founder who avoids the numbers with an invoice attached.
  • You are pre-revenue with a simple burn. There is nothing to be strategic about yet. Do the 30-minute monthly business review instead and keep the €4,000 a month.

If you do hire one

Three things separate good engagements from expensive disappointments:

Scope in writing. Deliverables per month: the forecast update, the board packet, the fundraise model. Vague retainers drift into invoiced availability.

Your numbers stay yours. You should still be able to answer runway, burn, and MRR from memory. The CFO adds judgment on top of numbers you both see, not a translation layer you depend on.

Start with a project. A fundraise model or a pricing review is a two-month test with a clear output. If the work is good, extend to a retainer. If it is slideware, you learned it cheaply.

The pattern worth stealing from companies that get this right: cheap tools keep the basic numbers live every day — that is the job of a runway model, or an AI agent grounded in it — and expensive judgment gets bought only for the decisions that deserve it.

Common questions

What does a fractional CFO do?

Strategy, not bookkeeping: building the model investors interrogate, forecasting and scenario planning, board and investor reporting, pricing and unit economics, and overseeing the bookkeeper and accountant you already have. Entering transactions, filing taxes and chasing invoices are accounting work — if someone sells CFO hours for those, you are overpaying by a factor of five.

When should a startup hire a fractional CFO?

When you are buying judgment for decisions with real stakes: raising a priced round with data-room questions past your depth, revenue past roughly €1M to €2M a year where pricing and hiring pace carry consequences, a board expecting reporting you cannot produce, or money moving in complicated ways — multiple entities, currencies, inventory, debt.

Do I need a CFO for my startup?

Usually later than it feels. If your questions are runway, burn and MRR, those are arithmetic, not strategy, and a model you keep current answers them for free. A CFO earns their cost when the questions become judgment calls: how to structure a raise, what to do about pricing, how to manage cash across entities. Buy visibility cheaply first, judgment when a decision deserves it.

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