Fractional CFO vs FP&A: Roles, Costs and When to Hire (2026)

Your seed round just closed. Your lead investor wants monthly numbers, and your board wants a plan for the next 18 months. One adviser says to get a fractional CFO. Another says you need FP&A. They sound alike, but they're different jobs at different prices. Here's what each one does, which one you need at each stage and when to hire a full-time CFO.

A fractional CFO is a part-time finance leader who makes the big money calls: the raise, the board, investors and cash. FP&A means financial planning and analysis. It does the work behind those calls: the budget, the forecast, the model and the monthly check of plan against actual. FP&A builds the numbers. The CFO decides with them.

What does a fractional CFO do?

A fractional CFO is a senior finance leader you share with other companies, for a few hours or days a month. They own strategy, fundraising, the board, investor relations and cash. They don't keep the books or build every forecast. They decide what the numbers mean: when to raise, how much runway to keep, which hires to slow.

Say your Series A is 9 months away. A fractional CFO sets the size and timing of the round. They build the case for your valuation, get the board ready and answer investors' questions in due diligence. Between raises, they watch cash and push back on spending. You're paying for judgment, not for hours in a spreadsheet. That's the work our fractional CFO services cover.

What does FP&A do?

FP&A builds the plan and checks it every month. It owns the budget, the forecast, the financial model, variance analysis and management reporting. Variance is the gap between plan and actual, plus the reason for it. At a startup, FP&A might be one analyst, a head of finance or an outside firm. Too often, it's the founder at midnight.

Say your plan had $110K of revenue in March and you booked $90K. FP&A finds out why: 2 enterprise deals slipped into April. Then it updates the forecast and shows what the gap does to cash. Notice what it doesn't do. It doesn't decide whether to cut spending or chase the deals harder. That's a CFO call, or the founder's.

You can hire for FP&A or buy it as a project. Our FP&A consulting sets up the model, the budget and the monthly review, then hands them to your team.

How do a fractional CFO and FP&A compare?

They differ in what they own, what they cost and who they report to. A fractional CFO owns decisions and reports to the CEO, working closely with the board. FP&A owns the numbers and reports to the CFO, or to the CEO until there is one. In 2026, Pilot's CFO plans start at $1,750 a month.

Look closely at what the cheapest CFO plans include. Pilot's entry tier covers an operating model, an annual budget, a forecast, runway and a monthly review. That's FP&A work, done by a CFO. Investor and board prep start one tier up. So a cheap CFO plan may be exactly the FP&A help you need. Just don't expect the entry tier to run your raise. We compare 10 firms on fit and price in our guide to the best fractional CFO companies.

Hiring in-house costs far more. Salary.com puts the average US CFO salary at $438,905, before bonus and equity. An FP&A manager's midpoint is $143,000 in Robert Half's 2027 guide. So buy both part-time until each becomes a full-time job.

Which one do you need at seed, Series A and Series B?

At seed, you need FP&A: a budget, a model and a monthly plan-vs-actual. Add a fractional CFO for the next raise. At Series A, hire a head of finance with FP&A skills and keep CFO help for the board and the round. Around Series B, hire a full-time CFO. CRV's 2026 hiring guide draws similar lines.

Seed — say you just closed a $3M seed and planned to burn $125K a month. From month four, burn runs at $160K: two hires started early and cloud costs doubled. A monthly plan-vs-actual catches it at once. The forecast shows runway falling from 24 months to about 19. That's FP&A work, and you don't need a CFO for it.

Start with our free startup budget template. If the model is the gap, buy the model, not a monthly retainer. Our financial models start from $3,000. Complex ones run $5,000–$15,000.

Series A — say you raised $12M and grew to 40 people. The board now meets every quarter and wants a real pack. CRV says Series A usually calls for a VP or head of finance. Bessemer's playbook adds a useful rule: if you must choose, hire FP&A skills over pure accounting. Keep a fractional CFO for board meetings and the Series B.

Series B — say you now run 2 legal entities, an audit is coming and a lender has offered venture debt. That's daily finance work. CRV puts the full-time CFO here, when multiple entities and audit readiness arrive.

How do a fractional CFO and FP&A work together?

They work as one monthly loop. The bookkeeper closes the books. FP&A compares actuals with the plan and updates the forecast. The CFO turns the gaps into decisions: hire, cut, raise or wait. Then the board pack and the investor update go out. In our work, skipped steps show up at the next raise.

This loop is what investors test. In our Fundraising 2025 study, 56 VCs named their top reasons to say no: revenue growth, unit economics, burn and missed milestones. Each one shows up first in a monthly plan-vs-actual. A missed milestone is often just a variance nobody explained.

The output is a short monthly pack. Our board deck template shows the format. A KPI dashboard keeps the metrics in one place. Agree on definitions once, like how you calculate run rate, so every report shows the same number.

Here's what weak FP&A can cost in a raise. An AI adtech startup had won investors over with its pitch. Then investors looked at the model and didn't buy the numbers. Revenue targets were top-down, there was no cash plan and unit economics were missing. We rebuilt the model in one week. The company closed its $6M seed round a month after delivery. A year later, it came back to us to forecast its Series A. Read the case.

Fractional CFO vs full-time CFO: when do you switch?

Switch when finance becomes a daily job. The usual signs are a Series B, more than one legal entity, an audit, debt or a sale. Another test is cost: when your fractional bill nears a full salary, hire. Start early. CRV plans roughly 10 to 16 weeks from search to start date.

Bessemer's CFO community put the switch in revenue terms. In its 2023 playbook, 37% of members surveyed named $10M–$25M of ARR as the sweet spot to bring on a CFO. A fractional CFO quoted in the same playbook gives a cost test. Switch once you spend 75% or more of a full-time salary on fractional help.

A fractional CFO can also bridge the gap. Bessemer's playbook tells how Webflow hired one to support the company during its CFO search. Ask yours to help write the job spec and to hand over the model and the board pack.