Two friends started a business together on a handshake and a rough 50/50 understanding, because writing anything formal felt like planning for a divorce before the wedding. For the first eighteen months it didn't matter — the business was small, the roles were obvious, and any friction got sorted over a pint. Then the business started genuinely working, a third person wanted to buy in, and it became clear that nobody actually knew, in writing, who owned what, who decided what, or what happened if one of them wanted out. That gap nearly ended both the friendship and the company.
Why it felt unnecessary at the start
When you start a business with a friend, a written agreement feels almost insulting — as if you're planning for the relationship to fail before it's begun. Everything's informal because everything's obvious: you built it together, you split things fairly, you trust each other completely. That trust is real and it's also exactly why nobody stops to write it down. The problem isn't the trust. It's that 'fair' means something different to each person the moment real money or real decisions are on the table, and nobody discovers the gap until it matters.
Where it actually broke
The moment it broke wasn't dramatic. An investor offer came in, and the two founders discovered they'd never actually agreed what 'roughly 50/50' meant in practice — one had assumed it accounted for the extra hours he'd put in during the first year when the other had kept a day job; the other assumed a clean, equal split regardless of history because that's what they'd shaken hands on. Neither was being dishonest. They simply had two different memories of an agreement that had never been written down, and no document to settle which one was right. The conversation that followed was the worst either of them had ever had, and it happened at the exact moment the business needed them working together most.
A handshake agreement isn't really an agreement. It's two people's separate memories of a conversation, which quietly diverge over time without either person noticing until money is on the table.
What a proper agreement should have covered
Looking back, the document that should have existed on day one didn't need to be complicated — it needed to cover four things clearly. Who owns what percentage, and on what basis if that ever changes (does someone earn more equity for extra hours, or does it stay fixed regardless of who does what week to week). How decisions get made, especially the ones that matter — spending above a certain amount, taking on debt, bringing in outside investment — and what happens if the two of you disagree. What happens if one person wants to leave, is forced to leave, or simply stops contributing what was expected, including how their share gets valued and bought out. And what happens if the business is sold, including whether both founders need to agree or a majority can force a sale.
The conversation is harder than the document
The document itself is the easy part — a solicitor can draft co-founder terms in a few pages once you know what you actually want it to say. The hard part is the conversation that has to happen first: sitting down while everything's still friendly and forcing yourselves to talk through the scenarios where it wouldn't be — what if one of us wants out in two years, what if we disagree about taking on investment, what if one of us just stops pulling their weight. Those conversations feel unnecessary and slightly paranoid when the business is small and the friendship is strong. They're dramatically easier to have then than after the disagreement has already started.
Why it matters more, not less, between friends
The instinct is that a written agreement is for business partners who don't fully trust each other, and unnecessary between friends. It's almost the opposite. Strangers going into business together tend to negotiate terms cautiously from the start, precisely because they don't assume goodwill will cover every gap. Friends assume the goodwill will always be enough, which is exactly what makes the eventual disagreement so much more painful — it doesn't just cost money, it costs the friendship the business was partly built to protect in the first place.
What we did once it nearly went wrong
The agreement eventually got written, after the argument rather than before it, which is a worse time to write one — trust had taken a real hit, and negotiating equity terms while still annoyed with each other is much harder than negotiating them as a formality on day one. It held the business together, but a version of that document written eighteen months earlier would have prevented the argument entirely rather than just resolving it. That's the real lesson: the agreement isn't there for when things go wrong. It's there so the version of the conversation that happens when things go wrong is 'let's check what we agreed' rather than 'let's work out, right now, under pressure, what we think we agreed'.
What we'd tell anyone starting out with a friend
If you're starting a business with someone you trust completely, that trust is exactly why it's worth writing the agreement — not despite it. Get proper terms drafted before any money changes hands or any real decisions get made, cover equity, decision-making, and what happens if someone leaves, and treat the conversation as a normal part of setting up a business rather than a sign the partnership is fragile. It isn't a vote of no confidence in the friendship. Done early and calmly, it's one of the things most likely to keep both the business and the friendship intact.
