The term sheet is signed. The investor is on the board, expectations are set, and tracking everything in a shared spreadsheet is no longer an option. Most startups at this point do not need a full-time CFO. They need someone who builds the finance function their investors will expect in the next due diligence: structured reporting, a model that holds up to scrutiny, and KPIs that actually reflect the business. A fractional CFO delivers exactly that, in a fraction of the time it takes to hire permanently.
What changes after Series A
Most founders underestimate the shift that an institutional investor triggers in finance requirements. A business angel rarely asks for structured numbers. A fund with a board seat expects monthly reports, variance analysis and forecasts that can be defended.
What is expected from Series A onwards:
- Monthly board reporting with P&L, cash position and three to five core KPIs
- Budget versus actuals with explanation of material variances
- Quarterly investor updates in a consistent format
- A continuously updated financial model used as an operational planning tool
- Documented unit economics: CAC, LTV, payback period and gross margins by segment
The difference between a productive and a tense board meeting often has nothing to do with the numbers themselves. It comes down to whether the founding team explains the numbers or gets explained by them.
Four finance gaps VCs see in portfolio companies
VCs managing multiple portfolio companies recognise the pattern. After Series A, the same four gaps appear almost regardless of sector or growth rate.
Reporting without structure
The company has monthly numbers, but they arrive in different formats, use different definitions and cannot be compared month over month. The investor gets no consistent picture at the board meeting. That creates doubt, and doubt tends to surface somewhere in the next negotiation.
An outdated financial model
The model built for fundraising was built for the presentation, not for running the business. Six months after closing, reality has diverged enough that nobody can plan with it. And nobody found the time to update it.
Inconsistent unit economics
CAC is calculated with certain cost items in some months and without them in others. LTV is based on a churn assumption that was never validated. Payback period is not tracked at all. When the VC asks, ad-hoc calculations produce slightly different numbers every time.
No cash transparency
The founding team knows the bank balance. But how much is committed, how runway shifts under different growth scenarios, and when the next fundraise needs to start: that lives somewhere between gut feeling and assumption. Investors call this flying blind.
What a fractional CFO builds in the first 90 days
The first three months follow a clear rhythm. No strategy decks, no extended diagnostic phase. What gets built are working processes:
| Phase | Deliverables | Outcome |
|---|---|---|
| Month 1 | Assessment of the current finance situation. First board reporting template. 13-week cash forecast. | The next board meeting runs with structure. |
| Month 2 | Financial model rebuilt or updated. KPI definitions fixed and documented. Budget versus actuals introduced. | Planning becomes an operational management tool. |
| Month 3 | Ongoing reporting processes established. Unit economics cleanly documented. Series B preparation started. | The finance function runs without constant intervention. |
These three months are a realistic timeframe when the right person takes on the mandate. A fractional CFO who has done this for twenty Series A companies does not need ramp-up time for the format, only for the business.
Why VCs actively recommend fractional CFOs for their portfolio companies
VCs managing multiple portfolio companies have learned that a fractional CFO closes the post-Series A finance gaps faster than any alternative. Three reasons dominate.
Speed. A full-time CFO takes three to six months to recruit and another month to onboard. A fractional CFO delivers the first board pack in week two. For a company with a board meeting in four weeks, that is not a difference in cost. It is a difference in operational capacity.
Pattern recognition. A fractional CFO who has worked with twenty Series A companies knows exactly what a lead investor wants to see at Series B. That knowledge does not come from a single full-time role.
Flexible capacity. Two days a week is enough in steady state. Ahead of a fundraising round or a due diligence process, the engagement scales up. That rhythm is difficult to replicate with a permanent hire.
The most common question I get from VCs is not whether their CFO can meet reporting standards. It is whether we can have it running before next month's board meeting. That is exactly where fractional wins.
Fractional CFO versus interim CFO in the VC context
The two terms are often used interchangeably. An interim CFO bridges a vacant position, typically works full-time and is scoped for three to six months. A fractional CFO builds the finance function and stays on as an ongoing resource, with capacity that adjusts to actual need.
For VC-backed growth companies, the fractional model is the better fit in most cases. The need does not disappear once the function is built, it changes. A fractional CFO stays for months and years, not just through a transition period. The full comparison is covered in the article on fractional CFO versus interim CFO.
When a full-time CFO is the better decision
Not every situation calls for a fractional CFO. Three scenarios where a permanent hire is the right choice:
- The company passes €8–10M ARR and plans a Series B or C where institutional investors expect a full-time CFO embedded in the team.
- The finance organisation needs to be built from scratch including team management, requiring daily presence over more than twelve months.
- An M&A process or structured exit is imminent and the CFO must act as a permanent counterpart in negotiations.
In all other cases: a fractional CFO is not the compromise, it is the right choice for the stage. When the transition to a full-time CFO makes sense is covered in more detail in the article on making the first CFO hire.