We sat down with a series of different investors over the past few months. A former private equity operator turned specialist VC. A serial founder who built and sold his way into the boardroom. A SaaS leader who now backs founders with her own capital and an angel investor, business leader and author who has spent decades watching businesses raise money well and badly. Despite different backgrounds there was a shared thesis about what they wish founders knew, especially regarding what angel investors look for in founders. Here is what came up again and again.

1. What angel investors look for first: clarity, not a polished deck

Every founder worries intently about the deck. Almost none of the investors we spoke to had the same concerns about the granularity. It is clarity that counts.

Deborah Young is a founding member of Alma Angels who has spent more than 20 years in SaaS and enterprise software. “Tell me the problem you’re solving, why this moment matters, and why you’re the person to do it. That’s it. I don’t need a deck that’s perfect, I need clarity.”

Alex Leigh, Managing Director at Future Planet Capital, sees the same thing from the VC side. Ask him what founders over-prepare his answer is the glossy pitch deck, and what he calls “buzzword bingo, trying to get investors hooked.” What they under-prepare is the part that actually matters, “clearly articulating the strength of their value proposition relative to existing alternatives.” The same lesson applies before the deck is ever opened, which is why it pays to know the mistakes that kill a startup’s investor pitch email before you make contact.

The anchor text “mistakes that kill a startup’s investor pitch email” carries the target keyword almost verbatim, which is what passes the most relevance signal. Want me to write it into the draft file?

Byron Crellin, who built and sold multiple businesses before moving into angel investing, framed it as a test you can pass in a few lines. “If you can communicate in a few lines what you do, why it matters, and why you’re the team to win, you’ve got an investor’s attention.” The lesson holds across all three. Time spent polishing animations is time not spent sharpening the one idea an investor needs to understand.

2. They are backing you, not your spreadsheet

At the earliest stages the numbers are too thin to carry a decision on their own, so investors fall back on the founder. This came through most strongly from the people who have signed the most cheques.

“At seed stage the metrics are too thin to make a purely analytical decision,” Crellin told us. He runs opportunities through four filters covering sector momentum, disruptive potential, standout appeal and a defensible USP, but he is candid about what tips the balance. “Some of my investments weren’t solely based on forecasted exit multiples, they were made because of the founder and their intensity, focus and their ability to execute.”

Young backs founders over sectors for exactly this reason. “The thread isn’t the sector, it’s the founder. I learned early that I can teach someone about markets or products, but I can’t teach conviction or character.” For a founder, that is oddly freeing. You do not need a flawless model to win the room. You need to show the judgement and grit that a model cannot capture.

3. What good angels bring beyond the cheque

It is one of the most common misconceptions about raising investment, and it came up again and again: founders treat the raise as a transaction and the investor as a source of money. The investors see it very differently.

“Founders underestimate what angels bring beyond cheque size,” Young said. “Many of us have 20+ years of scars in fundraising, M&A, and operations. We’re not just funding, we’re potential sounding boards, connectors, and problem-solvers. Build the relationship first.”

Crellin describes his own involvement as “stepping in, not just checking in,” bringing board-level discipline to help founders avoid the early mistakes that cost time and momentum. David Pattison, the angel investor and author of The Money Train, adds a useful distinction here. An individual angel chooses to invest, where an institutional fund has to deploy capital. That difference shapes how patient a backer is likely to be and how much they will roll up their sleeves. Understanding it changes who you should want on your cap table.

4. Investor-founder fit: do your homework on them too

Investors run due diligence on founders as a matter of course. The founders who impressed our four returned the favour.

Pattison is blunt about it. “Investors will carry out due diligence on you. Return the favour. Ask for references. Talk to the founders of other businesses they’ve backed. Find out what they’re like when things get difficult, not just during the honeymoon period. It’s not rude, it’s essential.” Getting this right is as much about negotiating with investors on equal terms as it is about choosing them in the first place.

Leigh points out that a huge amount of wasted time comes from founders who never checked the basics. “Are you in scope? Sector and stage. This is the main reason startups get rejected.” And Young, drawing on her experience as a Non-Executive Director, traces most founder and board breakdowns back to a missing conversation. Trouble starts “when they haven’t had a real chemistry and culture check during due diligence,” when both sides never actually aligned on what success in five years looks like. Byron has a name for the thing everyone is really testing for. We talk endlessly about Product Market Fit, he notes, and rarely about Investor Founder Fit. It deserves the same scrutiny.

5. Small behaviours end deals before the numbers do

Finally, a warning that founders rarely hear because it feels too obvious to say out loud. How you conduct yourself in the process is part of the process.

Leigh was the most direct. The behaviours that make him step away are not about the model at all. “Tardiness, especially as this is before you’ve even given them the money. Poor inter-founder interactions, as team risk is significant at the early stage. Rude behaviour or inflexibility, you need to know you can work together.” At the early stage, he says, you are committing to a relationship that can run for a decade, so you listen to your gut. Meanwhile Young watches for something subtler, how a team responds when market conditions shift, which she rates as the single thing that matters most. Neither of these shows up in a pitch deck. Both decide whether a deal happens.

The full picture

What unites these four is not a shared background, because they do not have one. It is a shared view of what actually moves them, and how little of it is the thing founders spend the most time on. Be clear. Show your judgement. Choose your backers as carefully as they choose you. Behave like someone worth working with for the next ten years.

We put the same questions to each of them and got a series of answers worth reading in full. Check out our investor insights section for more advice from those backing startups. Soon we will be publishing the results of our annual survey of investors to give you the full inside picture of what is driving the decision making of angel investors as we approach the Autumn fundraising season.

Are you looking for an angel investor to help fund your business? Join us at Angel Investment Network, where global investors meet the great businesses of tomorrow.