Most Series A startups need CFO-level work before they need a full-time CFO. Buy the model, the board pack, and the raise prep on a fractional or outsourced seat. Convert to full-time when the interaction is constant, complexity is daily, or you are in the ARR band peers treat as the hire window. Not legal, tax, or investment advice.
What each seat owns
Do not hire a titled CFO to do controller work. Kruze’s in-house guide separates the layers: staff accountant (bookkeeping, AP/AR, payroll support), controller (board-ready statements, close, tax oversight, systems), and CFO / VP Finance (modeling, fundraise strategy, valuation, advisory to CEO and board). Bessemer Atlas draws the same split as controllership versus FP&A: books right versus scenarios and capital allocation.
| Role | Owns | Does not replace | Source |
|---|---|---|---|
| Bookkeeper / staff accountant | Transaction categorization, AP/AR, payroll support | Model, raise narrative, board strategy | Kruze (in-house team guide) |
| Controller | Close, VC/board financials, tax compliance oversight, systems and controls | Full fundraise ownership and CEO partner seat | Kruze; Bessemer Atlas (controllership) |
| Fractional / part-time CFO | Model, KPIs, raise prep, board reporting, intermittent IR / debt / equity advice | Full-time presence and a growing accounting department | Kruze (when a startup needs a CFO) |
| Full-time CFO | Same strategic work, plus daily ownership of a growing finance org | Clean books without a controller underneath | Kruze; Bessemer Atlas |
A fractional CFO cannot fix a model built on messy books. Kruze puts accrual / GAAP-ready accounting under the strategy seat. Build the close first.
Stage triggers (who says what)
| Stage / frame | Typical finance setup | Who says so |
|---|---|---|
| Seed, gunning for Series A | Consider a part-time CFO at least 3 months before the raise | Kruze |
| Series A (general case) | No full-time CFO required. Outsource / fractional. Many shops have no CFO or VP Finance | Kruze |
| Series A–C | Part-time CFOs work well | Kruze |
| Series A, B2B SaaS sequence | CFO often months 12–24, or pre–Series B | Majhi Group (June 2026) |
| First full-time finance lead (complexity) | Complexity often around $5M–$10M ARR; some founders hold longer (~$20M ARR) | Bessemer Atlas (Kitching; Makarov) |
| CFO “sweet spot” (community poll) | $10M–$25M ARR (37% of Bessemer CFO Community) | Bessemer Atlas (Mar 2023) |
| Past Series D | Usually hire a full-time CFO to manage a growing accounting department; expect $240K+ cash | Kruze |
| Near IPO | Full-time CFO ASAP | Kruze |
Empty cells are intentional. Round labels and ARR bands come from different publishers answering different questions. Pair this with the Series A leadership hiring sequence when the board asks which exec seat comes first.
Cost bands (cited only)
| Item | Cited band | Source |
|---|---|---|
| Fractional CFO retainer | $5,000–$10,000 per month for ~10–20 hours of strategic work | Kruze (in-house team guide FAQ) |
| Full-time CFO / VP Finance base | $175,000–$350,000+ | Kruze (in-house team guide) |
| Seed-stage finance leader cash (Kruze note) | Often $150,000–$175,000 | Kruze |
| Series B+ CFO cash (Kruze note) | Often $250,000–$350,000+, equity commonly 0.5%–2% | Kruze |
| Full-time CFO after Series D (Kruze) | Expect $240K+ | Kruze (when a startup needs a CFO) |
| Controller base (startup building first internal finance) | $130,000–$180,000 | Kruze |
| Staff accountant base | $60,000–$85,000 | Kruze |
| Fully loaded three-person in-house team (staff + controller + CFO) | $450,000–$650,000+ cash/year before equity | Kruze |
| Break-even vs outsourcing (Kruze rule of thumb) | Do not bring the function in-house until outsourced billing exceeds roughly $35,000–$45,000 per month | Kruze |
fn-content has no verified benchmark atom for these metrics yet. fn-content tracks it as benchmark request: fractional vs full-time CFO hire timing and cost. Peer executive equity bands for other seats live on executive grants by stage. Runway math for the hire sits on the runway calculator.
Checklist: when to upgrade from fractional to full-time
Use these as yes/no signals. One yes rarely justifies the hire; several together usually do.
- Interaction is constant. Kruze: hire full-time when your interaction with the part-time CFO becomes consistent. Between raises, intermittent work is the norm.
- Fractional spend approaches a full-time package. Bessemer Atlas quotes fractional CFO Betty Kayton: transition when you are spending about 75%+ of a full-time salary on fractional support, or when operational / financial complexity is about to jump.
- You are in the ARR / sequence window peers name. Bessemer community: $10M–$25M ARR for many CFOs. Majhi B2B SaaS: months 12–24 after A, or pre-B. Kruze: often Series B, increasingly after Series C, depending on accounting quality.
- Complexity is daily. Multi-entity, international, audit readiness, high transaction volume, or a finance org that needs a manager on-site (Kruze exceptions; Bessemer complexity signals).
- IPO or major transaction is near. Kruze: near-IPO needs a full-time CFO ASAP.
- Hire for the phase. The operator who built the model for the A may not be the operator who runs a 20-person finance function toward B. Say the phase out loud in the offer (FounderNexus session).
If the board pack is still a scramble every quarter but books are clean, buy fractional first. The hiring sequence spoke works through that situation. Keep retention metrics honest on the pack with NRR vs GRR and efficiency with burn multiple vs Rule of 40.
Sources
- Kruze Consulting, When Does a Startup Need a CFO?. Series A generally no full-time CFO; part-time 3 months before a raise; Seed–Series A–C fit; hire full-time when part-time interaction is constant; past Series D often $240K+.
- Kruze Consulting, How to Hire a CFO for Your SaaS Startup. most Series A clients have no CFO or VP Finance; outsource until Series B (often after Series C); near-IPO needs full-time ASAP.
- Kruze Consulting, When to Hire an In-House Accounting/Finance Team. role layers and salary bands; fractional $5K–$10K/mo; three-person in-house $450K–$650K+; ~$35K–$45K/mo outsource break-even.
- Bessemer Venture Partners Atlas, How to hire a CFO and build a finance team. Mar 2023. Controllership vs FP&A; 37% at $10M–$25M ARR; complexity ~$5M–$10M; Kayton ~75% fractional spend rule.
- Majhi Group, Series A Leadership Team Benchmarks 2026. June 2026. B2B SaaS: CFO months 12–24 or pre–Series B.
- FounderNexus. founder session, February 2026. Hire for the phase. Say it in the offer. Not a survey.
- fn-content #14. benchmark request: fractional vs full-time CFO hire timing and cost.
Related
- NRR vs GRR for the board pack
- Burn multiple vs Rule of 40
- Runway calculator
- Series A leadership hiring sequence
- Executive equity grants by stage
The CFO seat is a phase hire. Founders who have upgraded from fractional to full-time (or held the line and raised without one) will pressure-test your timing in a FounderNexus session.