What a Series B Finance Team Should Actually Look Like
The Moment Finance Becomes Strategic
If you’re leading finance at a Series B startup, you’re standing at a turning point. The numbers aren’t just about basic record keeping anymore; they’re about credibility and audit-ready rigor. Investors are watching margins, auditors are reviewing your contracts, and the board is asking for reliable forecasts that don’t fall apart under scrutiny.
Series A was about growth at all costs. Series B is about discipline.
At this stage, many startups face the same challenge: they’ve built momentum, but not yet the infrastructure to sustain it. As Kyle Geers, Zeroed-In’s CEO, puts it:
“Most startup finance leaders hire when they’re underwater. But a peak workload, like audit season or technical memos, isn’t a reason to bring on a full-time hire.”
The right finance team structure for a Series B startup isn’t about headcount. It’s about sequencing and layering the right expertise at the right time so your systems, statements, and stories hold up to investor and auditor expectations.
The Core Team: What’s Essential at Series B
Think of your Series B finance team as a bridge, spanning the gap between a scrappy early-stage close process and a true controllership function built for investor-grade reporting.
1. The CFO (or Fractional CFO)
Your CFO, or a fractional equivalent, sets the tone for financial maturity. Their role moves beyond bookkeeping and reporting into leadership: building forecasts, defining capital strategy, and leading board-level communication.
Fractional CFOs help startups think strategically at a more flexible cost than a traditional full-time executive. For teams still in transition, this model offers high-impact financial leadership that scales with the business. For more info, check out our article, Why Choose Fractional Accounting Services Over a Full-Time Hire?
2. The Controller (or Fractional Controller)
This is the hire that most founders underestimate and either hire full-time too early or delay too long. Controllers enforce GAAP discipline, manage the close, and prepare your organization for audit readiness.
As John Ikosipentarhos, President at Zeroed-In Consulting, explains in his recent LinkedIn post:
“Hiring a full-time controller too early? That’s a six-figure mistake. Most growth-stage teams don’t need 40 hours of accounting oversight a week.”
Fractional controllership bridges the gap, offering deep accounting oversight and audit documentation without the overhead. It’s the model Zeroed-In Consulting used to help one fintech client transition from their first audit into a smooth second-year close. As one finance leader who benefited from this approach shared:
“They're really in that kind of perfect area where they're experienced enough to really add value and not need a lot of training, but not to experience really going to charge you a thousand dollars an hour, and they don't really want to roll their sleeves up." – Mark Lindsay
3. The Senior Accountant / Accounting Manager
Your operational backbone. This person owns daily entries, reconciliations, vendor management, and process discipline. As complexity grows, think multi-entity roll-ups or stock-based compensation, this role ensures accuracy before it hits the controller’s desk.
John often points to balance-sheet reconciliations as the quickest way to assess accounting health:
“If you can’t explain every number with supporting documentation, there’s a gap and it’s probably growing.”
Learn why clean reconciliations anchorsmart savings with outsourced accounting.
When to Layer in Specialized Support
Series B is when finance complexity outpaces headcount. You don’t need every role in-house; you need a flexible mix of expertise that expands or contracts as needed.
| Function | When to Add | Outsource vs. Hire |
|---|---|---|
| Technical Accounting (ASC 606, 842, Stock Comp) | Before the first audit or due diligence | Outsource – temporary project or retainer engagement |
| FP and A / Forecasting | When the board requests driver based modeling | Fractional until data cadence is consistent |
| Payroll and Equity Admin | As headcount and option pool expand | Hire – many equity and payroll functions can be handled in house with specialized software to reduce complexity |
| Audit Readiness | 3 to 6 months pre audit | Outsource – dedicated audit prep partner |
If your need is seasonal, temporary, or project-based, hiring full-time locks you into costs that won’t return value year-round. You don’t need a full-time hire to solve a part-time problem.
Curious about how technical accountant fees work? We wrote a candid article that walks through how pricing works for technical accountants and what to look for when hiring.
Why should I outsource my accounting instead of hiring another employee?
Let’s say you hire a Senior Accountant for $7k a month, you're usually getting one person with a specific set of skills. Let’s say you hire a Senior Accountant. They’ll handle some technical parts of the financials and help the accounting manager with other tricky topics. But for the same $7k a month with fractional support, you can get a mix of skills, and it’s typically a better bang for your buck.
Outsourced accounting firms can bring multiple roles and levels of expertise into a single one-stop shop. This way, you cover a broader range of skills and can adjust the work based on what you need at the time. No more worrying about your Senior Accountant doing tasks outside their expertise.
Watch the video below where Kyle explains how Zeroed-In typically coaches high-growth startups on when to hire full-time finance:
The Cost of Hiring Too Soon
It’s easy to overbuild once funding lands. But overstaffing early often creates a different kind of inefficiency: too many people doing work that could be automated or outsourced more effectively.
John notes:
“If your [accounting-related] workload is 15–20 hours a week, you don’t need a $200K controller. You need high-impact fractional support.”
Zeroed-In saw this firsthand with a fintech client who had only three internal team members managing hundreds of entities during their first audit. By supplementing that team with fractional technical accounting support, the startup avoided burnout, completed its first audit successfully, and transitioned seamlessly into fractional controllership the following year.
That model, fractional first, full-time later, gave them bandwidth and continuity.
The Audit-Ready Org Chart
A right-sized Series B finance team should balance permanent stability with flexible expertise. Here’s what an efficient structure typically looks like:
| Role | Core Responsibilities | FTE vs. Fractional |
|---|---|---|
| CFO | Strategic finance, fundraising, and board communication | Fractional or full time |
| Controller | GAAP compliance, close, policies, audit prep | Fractional or full time |
| Accounting Manager | Daily ops, reconciliations, process control | Full time |
| Senior Accountant | AR AP, journal entries, accruals | Full time |
| Technical Accounting Specialist or Audit Readiness Partner | ASC 606 842, equity, memos, coordination, documentation, and auditor liaison | Outsourced |
The goal isn’t to grow headcount, it’s to grow capability. A lean, well-sequenced team delivers the same output as a larger one, with fewer coordination gaps and faster close cycles.
How to Scale Cleanly Toward Series C
Once your processes and reporting cadence stabilize, the next phase is institutionalization: documenting everything, automating repeat tasks, and maintaining audit-ready hygiene month-to-month.
John calls fractional controllers the bridge to that state:
“Fractional controllers aren’t just a short-term fix. They’re the bridge to your long-term team.”
The same logic applies across functions. Technical accountants transition out once the memos are written and systems are in place. FP&A support becomes in-house when forecasting becomes a daily conversation, not a quarterly deliverable.
The mark of a mature Series C-ready team isn’t its size, it’s its consistency: clean processes, clear ownership, and zero surprises at audit.
Common Pitfalls to Avoid
Even strong Series B finance teams fall into familiar traps:
Hiring reactively. Don’t add headcount because audit season is busy, outsource instead.
Ignoring documentation. A great close means nothing if your policies aren’t defendable under GAAP.
Skipping auditor collaboration. Collaborate early. Your auditors are not your enemies.
Burning out your core team. Use fractional and outsourced support to prevent turnover during crunch periods.
Every hour you invest in proactive planning saves days in rework during audit season.
A Finance Function Built for Confidence
By Series B, investors expect more than growth; they expect maturity. Clean books, documented processes, and a team that can explain every balance on the sheet.
At Zeroed-In Consulting, we help finance leaders make that leap from reactive to ready. Our fractional controllership and audit readiness services are designed for high-growth startups that need to prove financial credibility fast, without the burden of overhiring.
You don’t need to build the perfect team overnight.
You just need the right support at the right stage.
Next Step: Build the Finance Function That Scales with You
Explore how a Fractional Controllership partnership can help you design the right team structure for your next stage of growth. Schedule a Discovery Call to connect with Zeroed-In consulting and get a tailored roadmap for your finance function.