Series B/C finance guide: Scale the machine

Crossing the valley of death from seed to Series A is no small feat. But getting to Series B is an even steeper climb—one that only around a third of Series A startups are able to complete. This is rarified air.

You’ve proven you can ship a viable product that people actually want, and you’ve proven that you can start scaling it efficiently. But how do the processes you built to scale from $1M to $10M of revenue hold up as you work to add another “0” to that number? 

This is much easier said than done. Middle management layers are getting hired and the executive team is losing touch with more and more of the action in the trenches. Left unchecked, this is the point where chaos can overwhelm your (still small) team, and finance is often best positioned to bridge the growing knowledge gaps across teams.

It’s time to step up. Finance needs to lead the charge in building an internal operating model that everyone can get behind, and it will have to do it through a collaborative budgeting process that meets teams where they are.

Series B/C do’s and don’ts

DO uplevel the finance team

Series B/C is when finance becomes responsible for establishing the company’s operating cadence—for their own sake, along with everyone else’s. They need to staff up and make sure the whole company can run the same play, every month, at a higher speed.

Here’s a high-level view of what your finance team composition will likely look like at this point…

Above is a page from our The evolution of finance orgs research report, breaking down the size and shape of finance teams at different sizes. This example is from the 50-250 segment where the B to C journey typically happens. Download the full report here.

…and a more specific look at the Series B/C stage:

• Early Series B: This is when your first finance hire comes on board—a VP that reports directly to the CEO. This person should either have direct experience scaling a company from Series C to D, or be an ex-investment banker who’s willing to roll up their sleeves.
• Late Series B/early Series C: Now it’s time to bring your accounting function in-house and hire a Controller or FP&A Manager. This person should complement the Finance VP’s skillset—if they have an FP&A background, this person needs significant accounting experience. If your Finance VP worked in accounting, then this hire needs strong FP&A chops.
• Late Series C: Whichever you haven’t hired yet—FP&A Manager or Controller—fill that position now. Also consider adding a billing/RevOps analyst for support. Depending on your funding, business size, complexity, etc., you may also consider hiring 2 more FP&A folks. One would be focused on topline/COGS, while the other hones in on Opex.

Some other things to keep in mind process-wise as you progress through this stage:

Have your Finance VP embark on a listening tour

If you’re like most startups at this stage, you’ve doubled or tripled your headcount in the span of a year. The way the company operates might be wildly different than it did at Series A.

Before making any substantive changes, send your VP of Finance on a listening tour to understand how people are working and identify their pain points.

Ask questions like:

• What’s the current source of financial truth? If it’s a gargantuan spreadsheet, that will be one of the first items you tackle. You need systems that can accommodate significant business changes without significant overhead.
• Who owns each number and its definition? And who’s the backup when that person is out?
• Which items still require manual reconciliation every month? Could software automate some or all of these?
• Where do handoffs stall between product, sales, marketing, finance, and HR? Could better systems eliminate these choke points?

Then, codify what you learn. Align on definitions, and assign a single owner for every KPI (and a backup). Getting a newly-expanded team on the same page isn’t easy, but establishing a shared language is a good way to start.

Make sure you can absorb new hires

At Series A, the question was “Can we afford this hire?” At Series B/C it’s “Can we absorb this hire?” In other words, does the organization actually have the ability to make this hire productive from the outset?

Before any team within the org opens a req, finance needs to check if they have the appropriate scaffolding in place:

• Recruiters to fill the seat on time
• A named manager with real bandwidth to coach and train the person
• Upstream capacity in design and product so engineering isn’t waiting around
• For sales hires, territories, leads, comp, tools, and a playbook in place before day one

This is best captured via a one-pager that spells out the work to be done, who leads it, the milestones, and what gets faster once those people land. If the team that’s hiring can’t answer that on paper, they’re not ready for a new person.

DON’T wait for Series D to get serious

An IPO still feels miles away. But if all goes according to plan, it could be here sooner than you think.

Now’s the time to start preparing yourself for that possibility. The habits you set today will shape your trajectory going forward, whether that's going public, a private exit, or a messy down round that's hard to recover from.

Your board is already starting to look for signs of public-company readiness, whether or not they explicitly state it. Can you close your books quickly and answer relevant questions with confidence? How about supporting capital-efficient growth across the org?

If not, here’s where to start:

Stand up a “forever data room”

Companies in earlier stages can often skate by with duct-taped diligence before board meetings. Now, it should start to feel like normal operating procedure. A standing data room is the kind of infrastructure that allows you to do that.

At Series B/C and beyond, everything needs to be audit-ready, all the time:

✅ Clean, current cap table
✅ Standardized revenue KPIs
✅ Documented security policies (SOC 2 included) 

“Forever mode” means you can pull up whatever number you need whenever someone important asks for it.

It’s also a culture signal. Investors will notice if finance operates as if it were already a public company. The opposite is true, too—one missing policy doc can raise eyebrows.

Make accounting a first-class citizen

It’s tempting to focus all your energy on sales. But Series B/C finance leaders need to bring accounting into strategic conversations early. 

Why? Because the second technical diligence starts, your ARR definition, revenue recognition, and audit prep will be under a microscope. If your accounting team isn’t looped in until the 11th hour, everyone is going to suffer.

Start doing these now:

• Schedule a standard review meeting with accounting every month
• Get alignment on what non-GAAP metrics to track, revenue recognition policies, and how to handle accruals
• Anticipate the questions that are coming, and make sure department leaders have the data and context required to answer them

Be consistent

No one’s handing out trophies for board deck creativity. Consistency and clarity are your highest virtues in a board setting.

Getting there requires you to:

• Close the books quickly so there’s time to understand the “why” behind the numbers
• Prep the board deck well in advance of the meeting
• Cover possible questions with key stakeholders before the meeting to avoid surprises.
• Anchor every narrative in numbers, not anecdotes.

All of this is a signal to investors that you run a tight ship built around predictable, repeatable processes.

DO build operating leverage into GTM

By Series C, finance shouldn’t just be tracking revenue. They should actively be helping sales earn it.

The brute-force sales tactics that might have worked earlier—adding reps, pointing them at quota, and repeating the process—will start to break down, if they haven’t already. 

Instead of just funding growth, finance needs to pressure-test it:

• Are those incremental dollars actually productive?
• Is each new hire building leverage, or just adding weight?
• How does this investment hold up when you run the CAC Payback math? (Does it get you to breakeven on customer acquisition in a reasonable timeframe?)
• What happens to contribution margin once you layer in infrastructure costs?
• Are AE productivity gains (quota attainment, ramp speed, churn impact) keeping pace with headcount growth?

Here’s how finance keeps GTM honest:

Sanity check rep models

A spreadsheet that says “10 reps × $1M = $10M” is hope masquerading as a plan. A robust model needs to incorporate actual ramp-up time, attainment history, and churn. If reps typically only hit 70% of quota and take 9 months to get there, your forecast needs to reflect that.

Find your leverage points

Growth doesn’t come from headcount alone. Finance should help sales and marketing leaders think about leverage points: better enablement, cleaner handoffs, more efficient tooling. If a new RevOps hire shortens ramp or improves forecast accuracy, that’s a real return.

Focus on unit economics that scale

Track CAC Payback and gross margin side by side. Fast payback doesn’t mean much if you’re giving away margin to get there. Finance should push for growth and efficiency—not just one at the expense of the other.

Enforce constraints

When teams ask for headcount or budget, don’t just ask “can we afford this?” Ask “how does this make us more efficient?” At this stage, every incremental dollar should drive operating leverage, not just top-line sugar highs.

DON’T chase vanity metrics

This is the point where finance needs to start calling out BS—internally and externally. Series B/C is where hand-wavy metrics go to die. That includes anything calculated off a string of rosy assumptions instead of real behavior.

LTV/CAC is the poster child for empty metrics. It might look great on a slide, but it often tells you more about your modeling optimism than your business reality. If you’re a 1 or 2 year old startup, how can you possibly know what your average customer’s lifetime value is? The numerator is a guess, and usually an overly-optimistic one.

We recently discussed this hot take on LinkedIn, “LTV/CAC is to GTM metrics what the DCF is to valuation: great in theory, unusable in the wild.” Especially at this stage. Churn is too lumpy, and growth is too nonlinear. The inputs are too subjective to mean much of anything.

Toss LTV/CAC to the side in favor of metrics that stand up to scrutiny and can drive real decisions:

• CAC Payback: Observable, intuitive, and grounded in real cash flows.
• Contribution margin: Critical to unit economics, especially as infra costs scale.
• Net dollar retention: If you have the cohort maturity to support it, this one’s worth tracking.

Here’s a rule of thumb to keep in mind: if a metric doesn’t tie back to how you actually acquire, retain, and expand customers, don’t let it drive strategy. Investors can smell fluff a mile away.

You’re in the big leagues now. Act like it.

You’ve reached a stratosphere that few startups ever come close to. But you can’t rely on momentum alone to continue your upward trajectory. Crossing the finish line—be it an IPO, strategic exit, or something else—requires a combination of operating discipline and efficiency.

Next up: what finance leadership should look like when IPO prep is around the corner.