What does "Series A" mean to us?
“Series A” is one of the most widely used phrases in venture capital and one of the most misunderstood.
Founders often treat it as a milestone: “We are raising our Series A round.”
Investors sometimes treat it as a category: “We only invest at Series A stage.”
In practice, Series A funding is not defined by the size of the round or the age of the company. It is defined by a shift in how capital is used.
Series A is about the transition to using capital to grow at pace.
At Guinness Ventures, we spend a great deal of time with founders at this stage. We invest in EIS eligible UK companies with over £1m in sales that are raising £1m or more of growth capital.
For us, a Series A fundraise is not the first large round. It is the first scaling round.
How does Series A funding compare to Seed funding?
Series A financing is typically used to move from testing to execution and to turn early customer demand into repeatable growth.
Seed funding is usually about proving something works by answering core questions such as:
- Is the problem real?
- Does the product solve it?
- Can you win customers?
- Do they stay?
- Do the economics work as the business grows?
Equally, we see Seed funding is the search phase. It is about reaching the early stages of product market fit.
Series A rounds are about building on that foundation.
What are Series A stage businesses expected to show?
By Series A stage, businesses are generally expected to demonstrate:
- A sales and marketing approach that wins customers and can be repeated
- Clear evidence of customer demand and retention
- Better visibility on pricing and how buyers make decisions
- A realistic plan for growth, including the key hires required to deliver it
The emphasis moves from exploration to execution.
What does Guinness Ventures look for?
As Series A stage investors at Guinness Ventures, we are not backing an idea or founders alone. We are backing the conviction that early customer demand can be converted into sustained growth.
This is why we focus closely on financial and operating data, including:
- A clearly defined customer group and the problem the product solves
- Evidence that customers actively use, renew and recommend the product
- Early signs that the business can grow economically, with customers paying for products and services
You can find more detail here: "Seeking Funding - what we look for".
Why is Series A funding different in the US?
You may come across commentary from US investors that describes Seed and Series A rounds as much larger than those typically seen in the UK.
In many cases, US seed rounds exceed the size of a UK Series A. This reflects differences in market scale, operating costs and funding dynamics rather than differences in company maturity.
The underlying point is the same in both markets. Stage is defined by where the business is operationally, not by revenue alone or the amount of capital raised.
Series A versus Series B and Series C
If Series A already carries multiple interpretations, these differences widen further at Series B and Series C. In broad terms:
- Series B funding is typically raised once product market fit is more established and capital is required to scale faster, often into new geographies
- Series C funding is usually associated with more established growth businesses, sometimes where acquisitions or significant balance sheet investment are required
Rounds labelled beyond Series C often reflect internal communication or marketing preferences rather than a universally accepted stage definition.
Why we invest in EIS and VCT eligible companies?
EIS and VCT funding is often discussed in the context of tax reliefs, but the eligibility criteria themselves provide a strong signal of business stage.
EIS and VCT eligible companies are typically early stage, UK based, ambitious businesses raising capital to grow. This aligns closely with our investment focus.
EIS and VCT eligibility also changes fundraising in practical ways:
- It broadens the pool of potential investors
- It supports greater appetite for early-stage investment risk
- It encourages longer term capital aligned with growth
Eligibility is not granted automatically.
Companies must meet specific legal requirements around age, size, trading activities, independence and use of funds. Many strong UK businesses do not qualify, often due to timing, asset thresholds or business structure.
What is the difference between EIS and VCT?
For founders looking to raise EIS or VCT capital, it is worth exploring the difference between the two funding types but generally if you qualify for one, you qualify for the other. We have recently produced a guide for investors on what the key differences are and will be producing a guide for founders soon. Stay tuned!
Looking to raise a Series A round?
If you’re a founder considering raising a Series A round, we’d love to talk. You’ll find more information on our website on what we look for (other than solely stage) and if you’re ready to get in touch please do make a submission.