The honest answer is that there is no official number, and anyone who gives you a confident single figure is selling something. What there is, instead, is a logic worth understanding before you reach for a target, because the number falls out of it rather than the other way round.
That logic starts with how early-stage returns are actually distributed. They don't average out. The great majority of seed companies return little or nothing, and a tiny minority return many times the cheque - enough to carry everything else. This is the power law, and it's the single most important fact about the asset class. If the returns live in a handful of rare winners, then the question "how many companies should I back?" is really the question "how many bets do I need before catching an outlier stops being luck?"
You're not picking the winner. You're buying enough tickets that one winner is plausible.
Why won't one or two investments do?
Because the base rates are brutal, and they don't care how good your judgement is. Put everything into one company and the most probable outcome - given how often early-stage businesses fail - is that you lose. Two cheques barely improve the odds. The point of a portfolio isn't to be busy; it's to give a low-probability, high-payoff event enough chances to occur that catching one becomes likely rather than miraculous.
Think of it the way an underwriter thinks about a book of risks. No single policy tells you whether the year was good. The spread does. An angel with three holdings is exposed to three specific founders, three specific markets, three specific moments in the funding cycle. An angel with twenty is exposed to the asset class. The first is a bet; the second is a strategy.
So what's the number people actually circle?
Among experienced UK angels, you'll hear figures in the range of a couple of dozen companies thrown around as the point where a portfolio starts to behave like a portfolio rather than a series of individual wagers. Some go further. The exact figure isn't the interesting part, and we're deliberately not going to dress one up as a rule - it's a function of two things you control and one you don't.
The one you don't control is the distribution itself: winners are rare, so more entries help. The two you do control are how much you can genuinely afford to lose, and how small each cheque can be while still buying a stake worth holding. Those two numbers, divided into each other, give you a count. A person who can commit, say, a fixed sum a year and write minimum-sized cheques will arrive at a very different portfolio from someone writing large ones - and neither is wrong. The mistake is starting from the count and working backwards.
Doesn't a bigger portfolio just mean more winners?
Not on its own, and this is where a lot of first-timers go wrong. Quantity only helps if two other things hold. First, each company has to be chosen with the same care as if it were your only one - diversification is not an excuse to wave through weak deals to hit a number. A portfolio of forty bad bets is just forty ways to lose. Second, the cheques have to be big enough that a winner actually moves the total. Spread your capital so thin that even a 20x return on one holding is rounding error, and you've diversified your way out of the upside you were diversifying to catch.
So portfolio size sits in tension with cheque size, and the two have to be solved together. There's more on the capital this really takes in our piece on how much money you actually need to start angel investing. The structural point: the count is a consequence of cheque size and budget, not a target to chase.
Should I build the whole thing at once?
Almost no one sensible does. Most angels pace their investing across years - a handful of deals annually against a fixed budget - rather than deploying everything in a single burst. Spreading entries across vintages (the year an investment is made) matters because market conditions swing. Commit all your capital in one frothy twelve months and your whole book carries that year's inflated valuations; spread it and you average across the cycle, the way a regular saver averages into the market.
Pacing buys something else, too: time to get better. Your tenth deal benefits from the nine before it. And it leaves dry powder for follow-on rounds in the companies that are working - which, in a power-law world, is often where the real money is made.
How do SEIS and EIS change the count?
Quite a lot, in practice, because they lower the net cost of every bet - and a cheaper bet means the same budget stretches across more of them. The two HMRC schemes, the Seed Enterprise Investment Scheme (SEIS) and the Enterprise Investment Scheme (EIS), reward backing young, qualifying companies, and they work on both ends of the distribution.
SEIS, aimed at the earliest companies, gives 50% income tax relief on up to £200,000 invested per tax year, with a three-year minimum hold. EIS, a rung up, gives 30% income tax relief on up to £1,000,000 a year - or £2,000,000 if at least £1,000,000 goes into knowledge-intensive companies (broadly, heavy-R&D businesses) - also with a three-year hold. Relief on both can be carried back to the previous tax year. So a meaningful slice of every qualifying cheque comes back before any company has succeeded or failed. When one fails, loss relief lets you set the capital lost, after deducting the relief already given, against income or capital gains - so the true cost of a wipe-out is well below the headline figure. And on the rare winners, gains on SEIS and EIS shares are exempt from capital gains tax if held three years or more and income tax relief was received.
Read that against the power law and the effect on portfolio size is direct: if each loss costs you less and each win is untaxed, the same pot of money safely supports a wider spread of bets. The schemes need advance assurance from HMRC before you invest, and the company issues an SEIS3 or EIS3 certificate afterwards for you to claim. You generally need to be a UK taxpayer for any of it to be worth anything. There are also company-side limits - on company age, size, employee count and how much a business can raise - and several of these changed from 6 April 2026, so check the current figures rather than rely on old ones: gov.uk venture capital schemes (EIS) and the HMRC guidance for investors.
None of this changes the underlying maths. Most of your companies will still struggle; relief doesn't make a bad business good. What it does is lower the cost of being wrong and leave the upside untaxed - which, in an asset class built on rare, large winners, is exactly the edge that makes a wider portfolio defensible rather than reckless.
The bottom line on the number
Stop hunting for the figure. Start from what you can lose without it changing your life, divide by the smallest cheque worth writing, pace the result across several years and several sectors, and keep some powder dry for the ones that work. The count that falls out the other end is your portfolio. It will look nothing like your neighbour's, and that's fine - the only number that was ever going to matter was whether you backed enough good companies to give an outlier room to appear.
Frequently asked questions
How many startups make an angel portfolio?
There is no legal or official number. The logic that most experienced UK angels work to is that early-stage returns are concentrated in a few rare winners, so a single cheque is a poor bet. A portfolio of many companies, often built over several years, raises the chance that at least one outlier lands. The right number for any individual follows from how much they can genuinely afford to lose and how small each cheque can be while still being worth the effort. This is general information, not advice on how to size a portfolio.
Is one or two angel investments enough to diversify?
One or two investments leave you heavily exposed to single outcomes, and because the great majority of early-stage companies return little or nothing, the most probable result of a tiny portfolio is loss. Diversification in angel investing comes from spreading capital across many separate companies, ideally across sectors and vintages, so that no single failure decides the outcome and a rare winner has room to appear. How wide that spread should be is a personal question best worked through with a regulated adviser.
Does a bigger angel portfolio mean better returns?
Not automatically. A wider spread raises the statistical chance of catching an outlier, but only if each company is chosen with the same care and each cheque is large enough that a winner moves the whole portfolio. Spreading capital so thinly that no holding matters, or backing weak companies just to hit a number, does not help. Quantity supports the maths; it does not replace judgement on each deal.
How do SEIS and EIS affect how many startups an angel backs?
SEIS and EIS lower the after-tax cost of each cheque, which can let an angel spread the same capital across more companies. SEIS gives 50% income tax relief on up to £200,000 a year and EIS 30% on up to £1,000,000 a year, and both offer loss relief when a company fails. Because part of every qualifying cheque comes back as relief, the net amount at risk per deal is smaller, which supports a wider spread. The reliefs depend on your circumstances, so take FCA-regulated advice and check the current HMRC rules.
How long does it take to build an angel portfolio?
Most angels build a portfolio over several years rather than in one go, pacing a fixed annual budget across a handful of deals a year. Spreading entries across vintages avoids committing all the capital into a single market mood, and it gives time to learn. Because exits in early-stage investing typically take five to ten years, a portfolio built steadily can take a decade or more to resolve fully.
The Carry is independent editorial journalism, not financial or investment advice. Nothing here is a recommendation to invest in any company or scheme. Tax treatment depends on your individual circumstances and current rules can change; figures cited are drawn from HMRC guidance current at the time of writing. Consider advice from an FCA-regulated adviser before investing.