Fractional CFO for Series B Companies: Scope, Cost, Hiring

Why Series B Companies Still Hire Fractional CFOs

Series B is the upper bound of where fractional CFO scope still works. Companies at $10M to $30M ARR typically have a controller and a senior FP&A hire by this point. The fractional CFO provides strategic finance leadership across audit prep, fundraise readiness, M&A activity, and the board-level financial narrative.

Past $30M ARR, most companies need full-time CFO leadership. The fractional model breaks because the work is too constant, the team is too large, and the strategic decisions move too quickly for part-time presence. Companies that try to extend fractional past $30M typically discover the limits the hard way.

Specific Scope at Series B

Series B fractional CFO scope is the most demanding tier of the fractional model. 25 to 35 hours per month covering:

• Audit ownership (annual audit relationship and SOX-readiness if applicable)
• Strategic FP&A leadership (3-statement model, 5-year plan, scenario planning)
• Quarterly board materials with sophisticated financial narrative
• Investor relations cadence with existing investors
• M&A activity (buy-side or sell-side preparation)
• Pre-IPO readiness work where applicable
• Treasury and capital structure decisions
• Tax strategy at scale (international, R&D credits, deferred comp)
• Department head finance partnering (often 4-6 standing meetings)
• Hiring and managing the controller, FP&A leads, and accounting team

Carve-outs: full-time CFO scope (board ownership of all finance), customer success or sales ops if those are not finance-coordinated.

Pricing Benchmarks at Series B

Marketplace pricing through Catalant or Bolster adds 25-40 percent on top.

Hiring Signals: When to Engage vs Hold Off

Engage when:

• Revenue is between $10M and $25M ARR and full-time CFO timing is unclear
• Audit complexity is increasing (multiple entities, international, complex revenue)
• M&A activity is on the horizon and the team has no M&A experience
• The board is signaling pre-IPO readiness or sale process within 18-24 months
• The current finance leader is a controller, not a CFO, and strategic gaps are showing

Move to full-time CFO when:

• Revenue is past $30M ARR with continued growth
• The company is filing for an IPO within 12 months
• M&A activity is recurring (multiple deals per year)
• Investor relations work has grown to 5+ hours per week
• The fractional CFO is consistently working 35+ hours per month and overage is becoming the norm

90-Day Milestones to Expect

Month 1: full audit readiness assessment. Gaps identified across revenue recognition, lease accounting, equity comp, and any segment-specific complexities. Board materials reviewed and rebuilt to public-track standards if applicable.

Month 2: 5-year financial plan with three scenarios. M&A pipeline review if applicable. Treasury and capital structure recommendation. First quarterly close run on accelerated timeline (e.g., 5 business days).

Month 3: audit kickoff or pre-audit readiness sign-off. Investor relations cadence established. Department head partnerships fully operational. Series C model started if fundraise is in scope.

The Pre-IPO and Sale Track Question

If the company is on a pre-IPO or sale track, the fractional CFO arrangement usually has 12-18 months of useful life. The work that comes with public-readiness (S-1 prep, audit committee, SOX implementation, IR function buildout) is full-time CFO scope. The fractional CFO often supports the full-time CFO search, runs the audit relationship through the transition, and stays as an advisor through the close.

For broader context, see fractional CFO vs full-time CFO and fractional CFO marketplaces for PE portfolio.

Where Fractional Series B Engagements Fail

The leading failure mode at Series B is hours scale. The retainer was sized for 30 hours per month at signing. By month 6, the actual work is 50 hours per month. The CFO is either burning out, billing surprise overages, or letting work slide. The fix: re-baseline at month 4-5 when the actual scope becomes clear, and either expand the retainer or transition to full-time.

The second failure mode is M&A activity that wasn't in the original scope. A buy-side acquisition discovery in month 8 of a 12-month retainer adds 80-120 hours of work that was not budgeted. The cleanest path is to scope M&A as a separate project on top of the retainer.

Picking the Right CFO at Series B

Series B fractional CFO selection is more demanding than earlier stages. Three filters matter most.

Have they run audit relationships at scale? Series B audit complexity often involves multiple entities, international operations, complex revenue recognition (ASC 606 nuances, multi-element arrangements), and equity comp accounting. CFOs who haven't owned a meaningful audit before often struggle in their first audit cycle at this stage.

Do they have M&A or pre-IPO experience? Series B is when M&A activity starts (add-on acquisitions, acqui-hires) and pre-IPO conversations begin. A fractional CFO without M&A experience or public-track exposure produces a ceiling on the role's value. Ask which transactions they've supported and what was their actual scope.

Can they manage a 5-person finance team? By Series B most companies have a controller, senior FP&A leads, accounting analysts, and possibly a treasury or tax specialist. The fractional CFO is managing all of them. Management depth matters more here than in earlier stages.

The trap to avoid at Series B is hiring a Series A CFO with 8-10 hours per month of bandwidth. The role demands closer to 30 hours per month of senior attention plus team management. Underpriced and underspecified engagements tend to fail in months 4-6 when the workload becomes visible.