The short answer
A fractional CFO is a senior finance leader who works for your startup part-time, usually a few days a month, instead of as a full-time hire. You get the judgement of someone who has built finance functions before (models, forecasts, fundraising, board reporting) for a fraction of the cost of a full-time CFO.
For most early-stage startups this is the sensible middle step: past the point where a bookkeeper is enough, but well before a full-time CFO makes financial sense.
This guide covers:
- What a fractional CFO actually does, and what they do not do.
- When a startup needs one, and when it does not yet.
- What it costs, how pricing usually works, and how it compares to the alternatives.
- How to choose one and make the first three months count.
What a fractional CFO actually does
The job is to turn your numbers into decisions. A bookkeeper records what happened; an accountant makes sure it is filed correctly; a CFO helps you decide what to do next. At an early-stage startup that usually means the following.
Financial model and runway
- Build a financial model that founders understand and investors trust: revenue drivers, hiring plan, costs and cash.
- Keep a rolling cash forecast so you always know your runway in months, not just your bank balance.
- Run scenarios: what happens if the round takes six months longer, or if you hire three engineers instead of five.
Fundraising preparation
- Prepare the numbers side of the pitch: the model, the use of funds, the key metrics and how they are defined.
- Set up the data room and answer investor due diligence questions.
- Review term sheets with you from a finance angle: valuation, dilution, option pool, liquidation preferences.
Reporting and the board
- Monthly management reporting: actuals against budget, burn, runway and the handful of metrics that matter for your business.
- Board and investor updates that are consistent from month to month.
Building the finance function
- Choose and connect the tools: accounting software, spend management, payroll, cap table. See Spend Management for Startups for how to set up spending controls.
- Work with your accountant and bookkeeper so the books close on time and are investor-ready.
- Set up the basics of banking and treasury. The Banking for Startups guide covers this in depth.
- Put the first controls in place: who approves what, and how payments are made.
Strategy and operations
- Pricing and unit economics: is each customer making or losing you money?
- Equity and incentives: designing the option pool and grants. See the ESOP guide.
- Tax structure decisions, together with your tax adviser. Tax 101 for Startups explains the taxes you will meet.
- Often, operations and go-to-market support: hiring plans, sales compensation, vendor negotiations.
What a fractional CFO usually does not do
- Day-to-day bookkeeping and invoice processing. That is a bookkeeper's job, and much cheaper per hour.
- Statutory filings and tax returns. Your accountant or tax adviser signs those off.
- Legal advice. A CFO can read a term sheet with you, but your lawyer drafts and negotiates the documents.
Fractional CFO, controller, accountant: who does what
| Role | Main question they answer | Typical stage |
|---|---|---|
| Bookkeeper | What happened? (recording transactions) | From day one |
| Accountant / tax adviser | Is it filed correctly and on time? | From incorporation |
| Controller | Are the numbers accurate, closed and controlled? | Usually from Series A, or earlier in complex businesses |
| Fractional CFO | What should we do next, and can we fund it? | Pre-seed to Series A, sometimes beyond |
| Full-time CFO | All of the above, full-time, plus leading a team | Usually Series B onwards, or earlier ahead of a large raise or listing |
When does a startup need a fractional CFO?
Signs it is time:
- You are preparing to raise a round and need a model and metrics that hold up in due diligence.
- Your runway is under 12 to 18 months and you are not sure exactly how long it is.
- Investors or the board are asking for reporting you cannot produce quickly.
- A founder is spending more than a day a week on spreadsheets instead of product or customers.
- You are making a big commitment: a large hire plan, a new market, a significant contract.
- The books are a mess and nobody owns them.
Signs it is too early:
- You are pre-revenue, with only the founders, and burn is small and predictable. A good bookkeeper and a simple cash sheet are enough.
- You have no decisions coming up that depend on the numbers.
What does a fractional CFO cost?
Prices vary a lot by country, experience and scope, so treat the ranges below as rough orientation from the market, not a quote. Ask each candidate for their own pricing.
How pricing usually works
| Model | How it works | Best for |
|---|---|---|
| Monthly retainer | A fixed monthly fee for an agreed number of days or a defined scope | Ongoing work: reporting, forecasting, board support |
| Day rate | You pay per day worked | Variable needs, or a trial period |
| Project fee | A fixed price for a defined deliverable | A financial model, fundraising preparation, a finance system set-up |
| Hourly | You pay per hour | Occasional advice calls |
Rough cost ranges
In Europe, a common arrangement for an early-stage startup is two to four days a month on a retainer. Depending on the market and the person, this often lands somewhere between a few thousand and around ten thousand euros a month. In the US and in the most expensive European cities, rates tend to be higher.
A one-off project such as a fundraising model is often priced as a fixed fee, scaled to its complexity.
How that compares
- A full-time CFO costs a full senior salary plus benefits, often equity, and a long hiring process. For most seed-stage companies that is hard to justify for the amount of CFO work there actually is.
- A fractional CFO gives you the same experience for the days you need it, with no recruitment risk, and you can scale up or down as the company changes.
- The real comparison is not cost per day, but the cost of mistakes avoided: a round raised on weak numbers, a runway miscalculated by three months, an option pool that has to be fixed later.
How to choose a fractional CFO
- Startup experience at your stage. Someone who has built finance functions inside startups, not only advised large companies.
- Fundraising experience. Ask how many rounds they have supported and what went wrong.
- Relevant business model. SaaS, marketplace, hardware and fintech all have different metrics and pitfalls.
- Clear scope and availability. How many days a month, how fast they respond, and what is included.
- Chemistry. You will share your worst numbers with this person. You should feel comfortable doing so.
Questions to ask in the first call:
- What would you do in the first 30 days?
- What do you need from us, and from our accountant?
- What does a typical monthly report from you look like?
- How do you price, and what happens if we need more or fewer days?
The first three months, done well
- Month one: get the books clean and current, build or fix the cash forecast, and agree the key metrics.
- Month two: build the financial model and budget, set up monthly reporting and the board pack.
- Month three: decide the fundraising plan or the next big decision, and put basic controls and tools in place.
After that, the work usually settles into a monthly rhythm: close, report, forecast, and support the decisions in between.
Talk it through
If you are wondering whether your startup needs a fractional CFO yet, I am happy to talk it through. I have built finance and ops functions in-house at startups and now do the same work fractionally. Book a free intro call on the Work with me page: no pitch, just an honest answer about where you are.
A note on sources and numbers
The cost ranges in this guide are rough orientation based on my own experience of the market, not a survey or a quote. Prices depend on the country, the person and the scope, so always ask for a specific proposal. This is general information, not financial, legal or tax advice. If you need help now, see the Work with me page.