Building a startup is an exciting challenge, but also one of the most demanding processes when it comes to securing financial resources. From the idea stage to exit, getting startup funding is one of the main concerns of any entrepreneur.
Whether you’re launching your project or in a growth phase, understanding how startup funding stages work will help you transform a good idea into a viable and scalable business.
In this complete guide updated for 2026, we analyse in detail the startup financing stages, the most common early stage funding sources, real investment ranges per round, the metrics that investors expect at each stage, and the main funding pathways, including public financing.
Sources of funding for a startup
There is no single way to fund startups. As the project evolves, needs change and so do the most suitable capital sources.
Below, we explain all the different types of startup financing in a practical and strategic way so that you can learn about them, compare them, and choose the one that best suits your needs.
1) 3F: Family, Friends & Fools
This source is usually the first way to secure startup funding in very early stages (idea or pre-seed stage).
It’s informal capital contributed by family, friends and close acquaintances. Although their contribution is usually limited, it helps finance the first steps without depending on demanding third parties or complex processes.
When to use it: when conceptualizing the idea and building a basic MVP.
2) Accelerators and incubators
These are structured programs designed to boost startups in early stages, but with important nuances:
- Incubators: accompany from the design of the idea and business model.
- Accelerators: support startups that already have a product or service and seek to scale rapidly.
You may be interested in ➡️ Business incubators: what are they and examples
Qué ofrecen:
- Seed capital or initial investment
- Mentoring and specialized training
- Access to investor networks
- Workspaces and events
This type of funding provides not only money, but also structure and very valuable connections when you’re looking to grow fast.
3) Public grants and institutional aid
Startup funding also includes numerous public aids and grants to finance startups, including specific innovation, technology and expansion lines.
Main programs (Spain context):
- ENISA: participatory loans without collateral or personal guarantees, aimed at innovative and scalable projects.
Access the ➡️ ENISA funding for startups and innovative companies: a complete guide
- CDTI: grants and aid for R&D projects, including programmes such as NEOTEC or stamps of excellence.
Access the ➡️ complete guide on the types of financing offered by CDTI and how to access it
- Programas europeos: such as the EIC Accelerator, which combines grants and investment components for projects with high international potential.
- Regional and local aid available through grant portals.
Advantages:
- Don’t dilute company ownership
- Can be combined with private capital
- Foster innovation and competitiveness
Common requirements: a clear project, well-defined business plan and, in many cases, a minimum private contribution.
4) Business Angels
Business angels are individual investors who contribute their own capital to startups with growth potential. They often invest in early stages (pre-seed or seed), and also provide:
- Sector experience
- Mentoring and contacts
- Credibility before future investors
Keys to attract them: have initial metrics or validated hypotheses and a solid pitch.
5) Crowdfunding
Crowdfunding is a collective financing method in which multiple investors contribute small amounts to fund a startup through digital platforms.
Main types:
- Rewards-based: contributors receive products or services.
- Equity crowdfunding: participants obtain equity in the company.
- Crowdlending: loan-type financing with interest payment.
Advantages:
- Validates the product or market demand
- Diversifies the investor base
- Can be a community accelerator
6) Venture Capital
Venture capital is one of the most common sources for funding startups in growth stages (advanced seed, Series A, Series B…).
VC funds invest significant sums in exchange for equity and expect high returns within a defined timeframe, supporting the company’s accelerated expansion.
Key characteristics:
- Strict due diligence processes
- Focus on measurable KPIs and real traction
- Strategic contribution and network
7) Bank loans for entrepreneurs
Although historically less used by startups due to collateral requirements, bank loans remain an option, especially when financial metrics are already consistent or when combined with public guarantees.
Key points:
- Lower capital dilution
- Financial cost (interest)
- Ideal for specific working capital or asset investment needs
8) Venture Debt
Venture debt is a type of hybrid financing that combines debt with an option for equity participation. This instrument complements venture capital rounds and offers:
- Lower dilution than a pure equity round
- Additional liquidity for scaling and capex
- Structured terms and, sometimes, warrants on shares
When it applies: after a Series A or when VC capital has been raised and extra capital is needed without opening another full equity round.
9) Private Equity
Private equity usually enters in more mature stages, often after Series B, when the company already has scaled models and seeks strategic expansion or market consolidation.
This type of funding may involve:
- Purchase of significant share packages
- Financial restructuring
- Preparation for an exit
Comparison: Summary of funding sources for startups
| Source | Type of capital | Typical stage | Dilution | Added value |
| 3F | Own/Informal | Idea | 0% | Quick access |
| Accelerators/Incubators | Seed | Pre-seed/Seed | Low-medium | Mentoring + network |
| Public grants | Non-dilutive | Early / Growth | 0% | Does not dilute capital |
| Business Angels | Equity | Seed | Medium | Mentors and contacts |
| Crowdfunding | Depends on type | Pre-Seed/Seed | Variable | Community and interest |
| Venture Capital | Equity | Seed → Growth | High | Scaling and network |
| Bank loans | Debt | Varied | 0% | Liquidity without dilution |
| Venture Debt | Convertible debt | Series A+ | Low | Less dilution |
| Private Equity | Equity | Advanced Series B | High | Restructuring and exit |
Funding stages for a startup
The development of a startup is structured in several startup financing stages, each with specific challenges and different financial needs:
Idea stage
This is the starting point of every project. The main objective is to transform an idea into a solid concept and begin defining the minimum viable product (MVP).
What you’re looking to fund:
- Idea development
- Initial research
- First prototypes
Common funding sources:
- Founder’s own capital
- 3F (Family, Friends & Fools)
There are no formal typical investment ranges in this stage; the focus is on validating hypotheses. Amounts are usually modest and aligned with very early operational costs (e.g., a few thousand euros).
Pre-Seed
At this stage there is already a functional MVP or advanced prototype. The objective is to validate the solution with the first users and get initial data that demonstrates market interest.
Pre-seed funding range 👉 25.000€ – 250.000€ (indicative range).
What you’re looking to fund:
- Technical product development
- First market tests
- Very early key hires
Common funding sources:
- Business angels
- Accelerators and incubators
- Public grants
- Crowdfunding (rewards or equity)
- Own capital portion
Seed
When the MVP has been validated and initial traction is observed, the seed round helps consolidate operations, expand the team and start generating recurring revenue.
Seed funding range 👉 100.000 € – 1.000.000 €
What you’re looking to fund:
- Marketing and customer acquisition
- Product improvement based on feedback
- Scaling first sales
Common sources:
- Business angels
- Micro-VC funds
- Equity crowdfunding
- Public grants and aid
- Accelerators providing capital and strategic support
At this point, investors look for clear signals of sustained interest in the product and initial metrics indicating growth.
Series A
The Series A round occurs when there are already repeatable results in customer acquisition and growing business metrics. The goal is to accelerate growth and consolidate the business model.
Series A funding range 👉 1 M€ – 5 M€
What you’re looking to fund:
- Scaling operations
- Entering new segments or markets
- Consolidating team and processes
Common sources:
- Venture capital (VC) funds
- Institutional investors
- Complementary venture debt
- Larger public grants
Series B
In the Series B stage, the startup wants to consolidate market leadership, expand internationally or diversify product/service.
Series B funding range 👉 5 M€ – 20 M€
What you’re looking to fund:
- International expansion
- Large marketing investments
- New product lines
- Infrastructure strengthening
Common sources:
- Growth VC funds
- International funds
- Private Equity
- Structured venture debt
You may be interested in → Venture Debt or Venture Capital?
Post-series B / Advanced expansion
After Series B, many startups advance to later rounds (Series C, D, expansion), receive Private Equity capital or prepare for exit (strategic sale or IPO).
Ranking after Series B 👉 >20 M€
What you’re looking to fund:
- Global consolidation
- Strategic acquisitions
- Capital market preparation
At this stage, investors look for mature businesses with stable revenues, robust margins and clear leadership in their niche.
Summary of financing stages for a startup
| Stage | Typical financing range | Average pre-money valuation | Expected dilution | Runway to cover |
| Idea | — | — | 0% | 3 – 6 months |
| Pre-seed | 25.000 € – 250.000 € | 0,5 – 2 M€ | 5% – 12% | 9 – 12 months |
| Seed | 100.000 € – 1.000.000 € | 2 – 5 M€ | 10% – 20% | 12 – 18 months |
| Serie A | 1 M€ – 5 M€ | 5 – 15 M€ | 15% – 25% | 18 – 24 months |
| Serie B | 5 M€ – 20 M€ | 20 – 60 M€ | 10% – 20% | 24 – 36 months |
| Expansion / Post-series B | > 20 M€ | > 60 M€ | 10% – 15% | 36 months or more |
Metrics and KPIs (what investors look at)
Investors make decisions based on metrics. KPIs allow you to objectively measure whether the business model is viable, scalable and sustainable over time.
Each startup funding stage requires different indicators. What is expected in a pre-seed round is not the same as in a Series A or Series B.
Most common KPIs in startup funding
Although not all apply to all stages, these are some of the most used indicators in startup financing processes:
- MRR / ARR: monthly or annual recurring revenue.
- CAC (Customer Acquisition Cost): cost to acquire a customer.
- LTV (Lifetime Value): total expected value of a customer.
- Churn: cancellation or customer loss rate.
- Burn rate: monthly cash consumption rate.
- Runway: months the company can operate with available cash.
- Gross margin: business gross margin.
- Growth rate: monthly or annual growth of users or revenue.
Not all these KPIs are required from the start. Their relevance increases as the startup matures.
Summary table of metrics and KPIs by startup funding stage
| Stage | Priority KPIs | What investors evaluate | Level of demand |
| Idea | Problem validation, market size, team profile | Clarity of the problem, real opportunity and team capacity | Low |
| Pre-seed | Functional MVP, active users, initial retention, burn rate, runway | Real market interest and execution capacity | Medium |
| Seed | Initial MRR, monthly growth, CAC, retention, burn rate, runway | Early traction and business model consistency | Medium-high |
| Serie A | ARR/MRR, growth rate, LTV/CAC, churn, gross margin | Scalability, efficiency, and repeatability | High |
| Serie B | ARR > €1 million, international expansion, EBITDA, stable churn | Market leadership and large-scale execution | Very high |
| Expansion | Positive EBITDA, cash flow, margins, revenue predictability | Profitability, financial strength, and exit potential | Maximum
|
Need help funding you startup?
Accessing funding requires strategy, planning and impeccable execution. At The Startup CFO we accompany you throughout the process: from defining the financial plan to preparing rounds, public aid and negotiating with investors.
Our team of experts will guide you in identifying the best options, preparing documentation and managing the application.
👉Tell us what stage your startup is in and we’ll help you analyse funding and growth options with a free initial consultation: Chat on WhatsApp
