The prenup principle I read this week that around one in three young couples are now signing prenuptial agreements. The advice from lawyers? Don't wait until you want revenge. That line stuck with me. Not because I spend my days thinking about divorce, but because I spend them thinking about business partnerships. And the parallels are uncomfortable. Most people who go into business together do so with optimism. They share a vision. They trust each other. They assume the relationship will last. So they skip the awkward conversations about what happens if it doesn't. Then something shifts. One person works harder. One person wants out. One person makes a decision the other hates. And suddenly you're in a room with lawyers, trying to untangle years of shared effort with no framework to guide you. I've watched this happen. It's expensive, slow, and it destroys businesses that were otherwise doing fine. What a partnership agreement actually does A partnership agreement is not a sign of distrust. It's a sign of clarity. It answers the questions you don't want to ask when things are good. Who owns what percentage? How are profits split? What happens if someone wants to leave? What happens if someone dies? What happens if you fundamentally disagree on direction? These are not hypotheticals. They are certainties, eventually. The only question is whether you'll have a framework for handling them or whether you'll be making it up under pressure. I worked with a pair of business owners last year who'd been running a consultancy together for four years. No written agreement. When one wanted to bring in a third partner, the other didn't. They spent eight months arguing about voting rights, equity splits, and decision-making authority. Eight months where neither of them was focused on the actual business. The irony? If they'd spent two hours writing down their assumptions at the start, the whole thing would have taken a week. The 72% problem Here's a number that should worry you: according to data from the Federation of Small Businesses, 72% of small business partnerships in the UK operate without a formal written agreement. That means nearly three quarters of partnerships are running on assumption, handshake, and hope. Hope is not a structure. It's a vulnerability. When I run diagnostic sessions through alira.london, one of the first things I ask about is governance. Who makes decisions? How are disputes resolved? What's the exit mechanism? The silence that follows tells me everything. People don't avoid these questions because they're lazy. They avoid them because the questions feel premature. Or pessimistic. Or awkward. But the best time to negotiate terms is when everyone still likes each other. When you're not negotiating from fear or anger. When you can be generous because you're not protecting yourself. That's the prenup principle. You write the agreement when you don't need it, so it works when you do. What should be in it I'm not a lawyer, and this isn't legal advice. But I can tell you what I've seen cause problems when it's missing. First, ownership percentages. Not "we're equal partners" but actual numbers. 50/50? 60/40? Based on what? Capital contribution? Time? Expertise? Write it down. Second, decision-making authority. Can either partner commit the business to a contract? Is there a spending threshold that requires both signatures? What happens when you disagree? Majority vote? Veto rights? External arbitration? Third, exit mechanisms. If one partner wants out, how is their share valued? Can the other partner buy them out? Over what timeframe? At what price? If you can't agree, who decides? Fourth, death and incapacity. Morbid, but necessary. Does the remaining partner have to work with the deceased partner's spouse? Their estate? Their children? Or is there a buyout clause? Fifth, non-compete and confidentiality. If someone leaves, can they set up a competing business the next day? Can they take clients? Staff? Intellectual property? These are not edge cases. They are the things that tear partnerships apart. The cost of not doing it People tell me they'll sort out the paperwork later. When they have more time. When the business is more established. When they can afford a proper lawyer. Later never comes. Or it comes in the form of a dispute. I've seen a partnership dissolve over a £15,000 disagreement that could have been resolved in an afternoon with clear terms. Instead, it cost both parties over £40,000 in legal fees and destroyed a seven-year working relationship. The agreement would have cost them maybe £800 and a few uncomfortable conversations at the start. That's the maths. That's always the maths. The emotional objection Some people resist this because it feels like planning for failure. Like you're already expecting things to go wrong. I understand the instinct. But consider this: you probably have insurance on your home, your car, your health. Not because you expect disaster, but because you recognise it's possible. A partnership agreement is insurance for your working relationship. It doesn't mean you expect betrayal. It means you acknowledge that circumstances change, people change, and having a plan is better than not having one. The couples signing prenups aren't less in love. They're just more realistic about the range of possible futures. What to do this week If you're in a business partnership without a written agreement, here's what I'd suggest. First, have the conversation. Sit down with your partner and talk through the five areas I mentioned: ownership, decisions, exits, death, and non-compete. You don't need to agree on everything. You just need to surface what you each assume. Second, write down your assumptions. Use the Decision Matrix tool at alira.london if you need a framework for weighing options. Get your positions on paper before you involve lawyers. It's cheaper that way. Third, book time with a solicitor who specialises in partnership agreements. Not next month. This week. Get a quote. Understand the process. Start it. The best time to do this was when you started the business. The second best time is now.