A fractional CFO is a chief financial officer who works for a company part-time, on a retainer or project basis, rather than as a full-time employee. "Fractional" refers to the share of their time the company buys: a few days a month instead of every day. The company gets senior judgment on forecasting, capital, pricing and reporting for a fraction of a full-time CFO's cost. The CFO usually works with several companies at once.
Fractional CFOs are most common in startups and growing companies that need CFO-level decisions before they can justify a full-time CFO's salary. In the US, most charge between $3,000 and $12,000 a month.
What does "fractional CFO" mean?
The word "fractional" describes the arrangement, not the seniority. A fractional CFO does the same strategic work as a full-time CFO, in fewer hours. You will also see:
- Part-time CFO: the same arrangement, an older name.
- CFO for hire: a general term for any CFO engaged on contract rather than employed. It usually means fractional or interim.
- Virtual CFO: a fractional CFO who works mostly remotely. Most do.
Two terms are not quite the same thing, and the difference matters when you compare offers:
- Interim CFO: full-time, but temporary. An interim CFO covers a gap, such as a departure, a transaction or a turnaround, for a few months.
- Outsourced CFO: usually a firm, not an individual, taking on the finance function for an established business, often alongside its accounting. "Fractional" usually describes a part-time senior individual embedded with a startup or scale-up. The line is blurry and partly marketing.
What does a fractional CFO do?
A fractional CFO works forward from the numbers. The accountant records what happened. The CFO decides what to do next. In a typical engagement, that means:
- Cash visibility. Building and running a 13-week cash flow forecast so the company knows its runway week by week, not just at month-end.
- The financial model. A driver-based 3-statement model that links revenue, costs, hiring and cash, so every plan can be tested before it is committed.
- Budgets and targets. Turning the model into an annual budget, then reporting actuals against it each month.
- Unit economics and pricing. Measuring contribution margin, customer acquisition cost and payback, and using them to decide what to sell and at what price.
- Board and investor reporting. A monthly board pack that shows what changed, why, and what management is doing about it.
- Fundraising and debt readiness. A model and data room that hold up in diligence, a clean cap table, and a plan for how much to raise and when.
- Managing the finance stack. Overseeing the bookkeeper, accountant and tools, and fixing the month-end close if it is slow or unreliable.
What a fractional CFO does not do
A fractional CFO does not replace bookkeeping, payroll or tax compliance, and should not be doing any of them. They sit above those functions and depend on them being reliable. If your books are months behind or inaccurate, fix that first: a CFO working from bad numbers produces confident, wrong decisions.
Fractional vs full-time vs interim vs outsourced CFO
| Typical cost | Best for | Where it breaks | |
|---|---|---|---|
| Fractional CFO | $3,000–$12,000 a month (US) | Startups and scale-ups that need senior decisions, not a full finance team | Not full-time. Wrong fit if you need someone to manage a finance team daily. |
| Full-time CFO | ~$230,000 average US salary, before bonus, equity and benefits | Larger companies with a finance team to lead, or preparing for IPO | Salary plus equity before the company's scale justifies it |
| Interim CFO | Day rate or monthly fee, higher per month than fractional | Covering a departure, a transaction or a turnaround | Ends by design. Knowledge leaves with them unless it is documented. |
| Outsourced CFO | Monthly fee, varies with scope | Established businesses that want to hand over the whole function | Less embedded in the company's decisions than an individual CFO |
| Controller | Varies | Accurate books, month-end close, controls | Looks backward. Does not forecast, price or model a decision. |
A controller owns the accounting function. A fractional CFO uses the controller's output to make forward decisions. If your numbers are late or wrong, hire the controller first.
How much does a fractional CFO cost?
Published rates in 2026, from our full guide to what a fractional CFO costs:
- US hourly: $150–$350 is the common band across published sources.
- US monthly retainer: $3,000–$12,000 a month, most often $5,000–$8,000. Early-stage packages of 8–10 hours a month run $1,400–$2,800.
- UK: £700–£1,400 a day, or £2,500–£8,000 a month.
Compare that with a full-time hire. A retainer of $5,000–$8,000 a month is $60,000–$96,000 a year: roughly 26% to 42% of a ~$230,000 average US CFO salary, before the full-time CFO's bonus, equity and benefits. In the UK, full-time finance director salaries run £130,000–£200,000 before bonuses and employer costs.
Pricing follows scope, not hours. A model that takes forty hours and prevents a bad pricing decision is not better value at eighty.
When should you hire a fractional CFO?
Four signals, any one of which is usually enough:
- You are raising within the next 6 to 12 months. Investors will test your model, your metrics and your cap table. The time to fix them is before the first meeting, not during diligence.
- You have crossed roughly $1 million to $2 million of revenue. The founder is still doing the finance, and decisions on hiring, pricing and spend now carry real money.
- You have taken on debt, or are about to. Covenants, reporting obligations and repayment schedules need someone who reads the terms and forecasts against them.
- Your board has started asking for things. Monthly reporting, a budget, a cash forecast, a view on runway. If nobody owns those, a fractional CFO usually does.
For the full-time decision, see our guide on when a startup should hire a CFO.
When a fractional CFO is the wrong answer
- Your books are not clean. Hire a bookkeeper or controller first. Otherwise you pay CFO rates for cleanup.
- You need a finance team managed every day. Once there are several people in finance who need daily direction, a full-time CFO is usually the right hire.
- You want someone to raise the money for you. A good fractional CFO prepares the company to raise. Introducing investors and negotiating on commission is a different job, done by brokers and placement agents.
Is a fractional CFO worth it?
It is worth it when a specific decision with real money attached is coming, and nobody in the company can model it properly. It is not worth it as a general "finance oversight" retainer with no defined outputs.
A simple test: at $6,000 a month, a fractional CFO costs $72,000 a year. Name the decision that engagement should improve (the size and timing of a raise, a price change, a hiring plan, a debt facility) and estimate what getting it wrong would cost. If that number is not comfortably larger than $72,000, the engagement is too early or too broad.
The second test is outputs. Before signing, ask what you will have at the end of the first 90 days. A reasonable answer looks like this:
| Period | What you should have |
|---|---|
| Weeks 1–2 | A diagnostic: what is reliable in your numbers, what is not, and what to fix first |
| Month 1 | A 13-week cash forecast, updated weekly, and a clear view of runway |
| Month 2 | A 3-statement model and an annual budget built from it |
| Month 3 | A monthly reporting rhythm: board pack, KPIs, actuals against budget |
If a prospective fractional CFO cannot describe their first 90 days in deliverables, keep looking.
How to choose a fractional CFO
Ask four questions:
- Have you worked at our stage and in our business model? A CFO who has run finance for a SaaS company at $2 million of revenue knows things a CFO from a $200 million manufacturer does not, and the reverse.
- Can I see a model you have built? Anonymized is fine. You are checking whether it is driver-based, readable and checks itself.
- What exactly is in scope, and what is not? Get it in writing: deliverables, cadence and the boundary with your bookkeeper and accountant.
- How does the engagement end? A good fractional CFO leaves systems and documentation that the next person, fractional or full-time, can pick up.
If you are assessing options now, our fractional CFO services page sets out how ControlFi scopes engagements. Established companies that want to hand over the finance function should look at outsourced CFO services instead.
Frequently asked questions
Clear answers to the questions founders ask most often.
It means part-time. A fractional CFO works a fraction of a full-time schedule for each company, typically on a monthly retainer, and often serves several companies at once.
Yes. The two terms describe the same arrangement. "Fractional" is the newer term.
A chief financial officer engaged on contract rather than as an employee. Most CFOs for hire work as fractional CFOs, who are part-time and ongoing, or interim CFOs, who are full-time and temporary.
Usually not. Most work as independent contractors or through their own firm, under a services agreement with a defined scope and fee.
It varies with scope. Early-stage packages can be 8–10 hours a month; larger engagements run to one or two days a week. Good engagements are scoped by deliverables and cadence rather than logged hours.
Usually much cheaper. A $5,000–$8,000 monthly retainer is roughly 26% to 42% of the ~$230,000 average US CFO salary alone, before bonus, equity and benefits.
Yes, with preparation: the model, metrics, data room, cap table and how much to raise. Most do not introduce investors or negotiate on commission, and you should be wary of mixing the two roles.
Yes. A fractional CFO does not replace bookkeeping or tax compliance. They rely on accurate books to make forward-looking decisions.
The short version
- A fractional CFO is a part-time chief financial officer, engaged on retainer or by project.
- They own forecasting, the financial model, budgets, board reporting and fundraising readiness. They do not do the bookkeeping.
- US retainers run $3,000–$12,000 a month, most often $5,000–$8,000: roughly 26% to 42% of a full-time CFO's average salary before bonus and equity.
- Hire one when a raise, debt or board demands are coming, or once revenue passes roughly $1 million to $2 million.
- Judge an engagement by the decision it improves and the outputs in its first 90 days.
Related reading
- What Does a Fractional CFO Cost? Published Rates Compared (2026)
- When Should a Startup Hire a CFO?
- 13-Week Cash Flow Forecast: How to Build One (2026 Method + Template)
Sources: rate and salary figures are from ControlFi's 2026 fractional CFO cost guide, which cites the underlying published sources. The 90-day outline and the cost-versus-decision test are ControlFi guidance, not survey data.