Most startups should hire a fractional CFO first and move to full-time only when the finance work becomes continuous rather than episodic. A fractional CFO — an experienced finance executive who works for you part-time, usually a few days a month under contract — covers the forecasting, fundraising prep, and reporting discipline that early companies need, without the cost or commitment of a senior full-time hire.
The decision is less about company stage or headcount than about the shape of the work. If your finance needs spike around a raise, a board meeting, or a pricing change, a fractional engagement fits well. If finance has become a daily operating function with a team under it, part-time coverage starts to cost you more in delay and handoffs than it saves in salary.
Table of Contents
- What a CFO actually does that a bookkeeper or accountant does not
- Signals that a fractional CFO is the right call
- When part-time coverage starts costing you more than it saves
- Comparing the real cost, not just the invoice
- A sequence most startups can follow
- Questions to ask any candidate, fractional or full-time
- Frequently Asked Questions
What a CFO actually does that a bookkeeper or accountant does not
Founders often conflate three different roles. A bookkeeper records transactions and keeps the ledger clean. An accountant closes the books, files taxes, and prepares financial statements. A CFO uses those outputs to make decisions: pricing, hiring pace, cash runway, capital structure, and what to tell investors.
This matters for the hiring question because many founders who think they need a CFO actually need a competent bookkeeper and a responsive tax accountant. If your books are late, your categorisation is inconsistent, or you cannot say what last month's gross margin was, a CFO will spend the first months fixing accounting hygiene — at CFO rates. The reverse mistake is also common. A founder with tidy books but no financial model, no view of unit economics, and no plan for the next eighteen months of cash has a CFO-shaped gap, and no amount of bookkeeping will close it.
Signals that a fractional CFO is the right call
Fractional engagements work best when the problem is expertise density, not volume. You need someone who has built a model that survived diligence, sat in front of a board, and negotiated with a lender — and you need that judgment for ten hours a month, not 160.
Common fits: A fractional CFO is also a reasonable way to find out what you actually need. Six months of part-time work usually reveals whether the role is a recurring executive function or a project that ends.
- You are preparing a priced round or a bank facility and need the model, data room, and narrative to hold up.
- Your revenue is growing but you cannot explain why margins move the way they do.
- An investor or lender has asked for reporting you do not currently produce.
- You need someone to own the budget and forecast, but there is no finance team to manage.
- Your cash position needs a real runway plan rather than a bank-balance check.
When part-time coverage starts costing you more than it saves
The limits of fractional work are structural, not about effort. A part-time executive is not in the room for the unplanned conversations where decisions get made, cannot respond inside an hour when a deal term changes, and divides attention across other clients.
For most early-stage work that is fine. In some situations it is not. Move toward full-time when: There is also a quieter signal: if you find yourself waiting for your fractional CFO's next session before making routine decisions, the engagement has outgrown its format.
- Finance has staff to hire, manage, and develop — fractional CFOs rarely build and run teams well.
- You are operating in a regulated environment, or approaching an audit, where ongoing controls work is constant.
- Transaction volume, multi-entity structure, or international operations make the close itself a demanding monthly project.
- You are in a sustained process — an acquisition, a complex financing, a restructuring — where someone must hold context full-time.
- Investors have made a full-time finance leader an explicit condition.
Comparing the real cost, not just the invoice
Fractional work is usually billed monthly or hourly, and the headline figure is smaller than a senior salary. But compare total cost of employment, not salary alone. A full-time CFO carries payroll taxes, benefits, equity dilution, recruiting fees, and the cost of the role being wrong — a mis-hire at that level is expensive to unwind and visible to your board.
Against that, weigh what a fractional arrangement does not give you: continuity, institutional memory, and someone whose incentives are tied to your equity rather than a retainer. Equity is part of why full-time CFOs take the risk of a startup, and it is also why they expect decision authority when they arrive. Rates vary widely by market, sector, and the seniority you are buying, so ask for a scope and a monthly ceiling rather than an hourly rate in isolation. The useful question is not "what does this cost per hour" but "what decisions will be better in ninety days, and how will we know.".
A sequence most startups can follow
Treat this as a progression rather than a single hire. The order matters because each step makes the next one cheaper and better informed.
- Get bookkeeping right first, with a monthly close that lands on a predictable date.
- Add a tax accountant or outsourced controller when compliance and the close take real time.
- Bring in a fractional CFO for the model, the forecast, and whatever capital event is next.
- Define the scope in writing: deliverables, meeting cadence, board involvement, and what is out of scope.
- Review after two quarters, asking whether the work is still project-shaped.
Questions to ask any candidate, fractional or full-time
Ask for specifics about companies at your stage and in your model. A CFO whose experience is enterprise SaaS may be excellent and still be learning on your marketplace or hardware business. Ask what they got wrong at a previous company and what they changed afterwards — vague answers here are the most reliable warning sign. For fractional candidates, ask how many clients they currently hold, who does the work when they are unavailable, and what happens to your institutional knowledge at the end of the engagement.
Ask whether they will attend board meetings and in what capacity, because founders are frequently surprised to learn that is billed separately or not offered. For full-time candidates, be honest about the scope. A CFO hired to raise a round and then handed accounts payable and office management will leave. Write down which of the three roles — bookkeeping, accounting, financial leadership — you are actually filling, and make sure the person you hire agrees.
Frequently Asked Questions
Can a fractional CFO help us raise a round?
Yes — fundraising prep is one of the most common reasons founders engage one. Confirm in the scope whether they will join investor calls and diligence sessions, or only build the model and data room.
Do we still need a bookkeeper if we hire a CFO?
Almost always. CFOs interpret and plan; they do not want to be categorising transactions, and paying them to do it is poor value.
How do we transition from fractional to full-time without losing continuity?
Overlap them deliberately. Ask the fractional CFO to document the model, close process, and reporting pack, then stay on for a short handover period after the full-time hire starts.
Is a VP of Finance a cheaper alternative?
Often, yes. A VP of Finance typically owns reporting, planning, and the close full-time but without board-level capital markets experience — which pairs well with a fractional CFO for fundraising.