Series B: What is a Series B Funding Round?

What is a Series B Funding Round?

Series B is a funding round that follows Series A and marks the startup's entry into an accelerated growth phase. At this stage, the company has already demonstrated product-market fit, reached critical mass in terms of revenue and team size, and now seeks to dominate its market. Series B amounts typically range from 10 to 30 million euros in Europe, with pre-money valuations often exceeding 50 million euros.

Series B investors are growth equity funds specialising in supporting scale-ups. In Belgium and Europe, these include players like Sofina, Fortino Capital for larger rounds, as well as pan-European funds like Accel, Highland Europe or Eurazeo. Investors from previous rounds (seed and Series A) generally exercise their pro-rata rights to maintain their stake.

The transition from Series A to Series B represents a radical change in scale. The company moves from a growing startup to a scale-up that must operate like a mature enterprise, with industrialised processes, a complete management team and a clearly defined expansion strategy.

Why Series B Matters

Series B is the fuel for market domination. It enables a startup that has proven its concept to become the undisputed leader in its segment. The stakes of this round are considerable:

• International expansion: Series B typically finances opening new geographic markets, establishing local offices, recruiting regional sales teams and adapting the product to local specificities.
• Market domination: investing heavily in marketing and sales to capture the largest possible market share before competitors establish themselves.
• Technology consolidation: refactoring and strengthening the technical platform to support 10 to 100 times higher volumes with enterprise-grade reliability and security.
• Product diversification: expanding the offering with new features, modules or complementary products to increase average revenue per user (ARPU).
• Strategic acquisitions: using funds to acquire complementary companies (technology, customer base, talent) that accelerate growth.

How It Works

The Series B fundraising process is the most rigorous of all early-stage rounds. Growth equity investors have experienced analyst teams evaluating every company aspect with near-surgical precision. Due diligence can last three to six months and cover dozens of dimensions.

The metrics expected in Series B are demanding. Investors typically seek ARR of 3 to 10 million euros, annual growth above 100%, LTV/CAC ratio above 3, net revenue retention (NRR) above 120% and a credible path to profitability. The company must also demonstrate a defensible competitive advantage: proprietary technology, network effects, high switching costs or strong brand.

Series B investment terms include sophisticated protection mechanisms: cumulative liquidation preferences, enhanced anti-dilution rights, change of control clauses, board representation rights proportional to stake and sometimes milestones conditioning investment tranche release.

Governance evolves significantly: the board of directors expands to 5 or 7 members including representatives from each funding round. Specialised committees (audit, compensation, strategy) are established and reporting processes professionalise with indicators tracked monthly.

Concrete Example

Let us continue the story of our e-commerce logistics startup. Three years after its Series A, the company has reached 5 million euros in ARR, operates in four European countries (Belgium, Netherlands, France, Germany) and employs 80 people. The technical platform, evolved from the solid foundations laid by KERN-IT, now integrates machine learning algorithms for predictive delivery optimisation.

The founding team launches a Series B process to raise 15 million euros. The objective: open the British market, develop a complementary returns management product and recruit 50 additional people. After a competitive process involving six funds, Accel leads the round at a 60 million euro pre-money valuation. Sofina and Fortino co-invest alongside all historical investors.

The technical audit conducted during due diligence highlights the quality of the initial architecture that enabled scaling without major overhaul. The technical choices made from the MVP stage with KERN-IT — modular architecture, well-documented APIs, separation of concerns — allowed the internal technical team to evolve the platform without excessive technical debt accumulation.

Implementation

1. Demonstrate unit economics: prove that each acquired customer generates a positive return — LTV/CAC ratio above 3, payback period under 18 months, gross margins above 60%.
2. Build a complete leadership team: recruit a VP Sales, VP Engineering, VP Marketing and CFO before Series B. Investors want to see a team capable of managing upcoming growth.
3. Industrialise processes: implement repeatable processes across all functions — sales, customer onboarding, support, recruitment — with clear KPIs measured regularly.
4. Prepare international expansion: validate demand in target markets before the raise, ideally with initial pilot customers, to demonstrate the model is replicable.
5. Strengthen the technical platform: invest in scalability, security, monitoring and technical documentation to pass the most demanding due diligence audits.
6. Structure governance: establish a functional board, specialised committees and detailed monthly reporting to demonstrate organisational maturity.

Associated Technologies and Tools

• Cloud infrastructure: AWS, Google Cloud or Azure with auto-scaling, multi-region deployment and disaster recovery to guarantee availability at international scale.
• Observability: Datadog, PagerDuty and Sentry for comprehensive monitoring covering infrastructure, application and user experience with documented SLAs.
• Data infrastructure: Snowflake, dbt and Looker to build a solid data warehouse providing the business intelligence metrics investors expect.
• Collaboration tools: Notion, Linear and Slack to coordinate a team distributed across multiple countries with standardised work processes.
• Security: SOC 2, ISO 27001 and regular penetration audits to meet security requirements of enterprise customers and investors.

Conclusion

Series B is the moment when a Belgian startup transforms into a European scale-up. This funding round demands exhaustive preparation and rigorous demonstration of the company's ability to scale on all fronts: product, technology, commercial and organisational. The technical foundations laid during the earliest development phases play a determining role: a well-designed architecture from the MVP stage avoids costly refactoring that slows growth. At KERN-IT, we design technical platforms with this long-term vision, knowing that today's architectural choices will determine our clients' ability to raise and scale tomorrow.