The Role Most Founders Underdefine
A fractional CFO is not a part-time bookkeeper or a glorified controller. The role covers strategic finance leadership, and the scope is wider than most founders assume when they hire one. Understanding what a fractional CFO actually does, and where the role ends, makes the engagement productive from week one.
Core Responsibilities
Cash flow management and forecasting. The fractional CFO owns the 13-week cash forecast, the burn rate analysis, and the runway projection. They flag cash issues before they become crises and design responses.
Financial planning and analysis (FP&A). The fractional CFO builds and maintains the financial model: revenue projections, cost models, headcount plans, scenario analysis. They run the budget process and quarterly reforecasts.
Board and investor reporting. The fractional CFO produces the board package: financial statements, KPI dashboards, narrative commentary, and forward-looking commentary. They often present finance directly in board meetings.
Fundraising support. The fractional CFO leads the financial side of fundraising: model preparation, due diligence prep, data room organization, and investor Q&A. Many fractional CFOs have led 10 to 20 fundraises.
KPI design and dashboarding. The fractional CFO defines the metrics that govern operational decisions: unit economics, CAC, LTV, gross margin, contribution margin, working capital. They build the reporting cadence around them.
Financial controls and audit readiness. The fractional CFO designs financial controls, ensures audit readiness, and oversees the relationship with external auditors when applicable.
Strategic finance. The fractional CFO advises on pricing decisions, contract terms, M&A consideration, capital allocation, and other decisions with significant financial implications.
What a Fractional CFO Doesn't Do
Daily bookkeeping. The fractional CFO does not enter transactions, reconcile accounts, or close the books day to day. That work belongs to a controller or external bookkeeping firm.
Accounts payable and receivable processing. Vendor payments, customer invoicing, and collections sit with the controller or finance ops staff.
Detailed accounting policy work. Specific accounting treatments (revenue recognition, lease accounting, complex consolidations) often require specialist support, especially for audit prep.
Tax preparation and filing. Most fractional CFOs work with external CPAs for tax. They oversee the relationship but don't prepare returns.
Typical Org Structure with a Fractional CFO
For a Series A through Series B company with a fractional CFO, the finance org usually looks like this:
- Fractional CFO (15-25 hours per week): strategy, board, fundraising, FP&A.
- Controller or senior accountant (full-time): close, AP/AR, financial controls, day-to-day accounting.
- External CPA firm: tax, audit support, complex accounting policy.
- External bookkeeping firm or in-house bookkeeper: transaction entry, reconciliations.
This structure costs $250,000 to $400,000 annually all-in. A full-time CFO doing the same work costs $500,000 to $700,000 loaded.
What a Typical Week Looks Like
For a fractional CFO at 20 hours per week:
- Monday (4 hours): Cash review, AR aging, weekly KPI dashboard, anomaly flags.
- Tuesday (3 hours): One-on-one with controller, review month-to-date close progress, address open issues.
- Wednesday (4 hours): Strategic finance work (pricing analysis, scenario modeling, vendor negotiation support).
- Thursday (4 hours): Executive team meeting, finance review of operating decisions, deep work on board materials or fundraise.
- Friday (5 hours): Board prep, investor communications, retrospective and planning for the next week.
How a Fractional CFO Differs from Adjacent Roles
| Role | Primary Output |
|---|---|
| Fractional CFO | Strategic finance, board, fundraising |
| Controller | Close, AP/AR, financial controls |
| Bookkeeper | Transaction entry, reconciliations |
| External CPA | Tax, audit support |
| VP Finance | Full-time strategic finance plus FP&A team |
For more context, see fractional CFO cost breakdown, fractional CFO vs full-time CFO, and when does a startup need a fractional CFO.
FAQs
Can a fractional CFO close the books each month?
Generally no. Closing the books requires daily attention that doesn't fit a fractional engagement. The fractional CFO oversees the close process but a controller or external bookkeeping firm executes it.
Does a fractional CFO handle audits?
Yes. Most fractional CFOs lead audit preparation and manage the relationship with external auditors. The controller and CPA firm handle the detailed accounting work. The fractional CFO is the strategic point person.
Can a fractional CFO lead a fundraise?
Yes, and many do. Most fractional CFOs have led 10 to 20 fundraises. The scope includes financial model preparation, investor materials, due diligence management, and term sheet evaluation.
What's the difference between a fractional CFO and a fractional controller?
A fractional controller manages the close, AP/AR, and accounting controls. A fractional CFO handles strategic finance, board reporting, fundraising, and FP&A. The controller is operational. The CFO is strategic. Both roles can be fractional but the scope and pricing differ significantly.
How many companies can a fractional CFO work with simultaneously?
Most fractional CFOs work with 3 to 6 clients at any given time. At 15 to 25 hours per client per week, they hit a natural ceiling around 5 to 6 engagements. More than that and engagement quality degrades.