How to Create a Co-Founder Agreement
+3 templates to steal + free 15min brand consultation
Read time: 4min
So…
You’ve found your co-founder.
If you haven’t, go back there: 5 things to know before picking a co-founder.
Now what?
The energy’s good.
The banter’s flowing.
The vision’s bold.
Time to build.
Time to raise.
Time to… figure out the legal stuff.
That’s where most founders flinch.
And I get it.
Talking equity splits and IP clauses doesn’t feel nearly as fun as sketching a landing page or imagining your product changing the world.
But here’s the truth:
Every startup breakup I’ve seen started with fuzzy expectations and no written agreement.
This one doc protects your entire journey
Your co-founder agreement =
the prenup of startups.
It won’t stop the storms from hitting.
But it will keep the ship from sinking when they do.
So let’s get tactical.
1. Equity Split
Don’t go 50/50 by default.
Ask:
Who built what?
Who’s full-time now?
Who took a pay cut?
Who’s taking the early risk?
Split based on contribution.
See how to split equity among co-founders.
And read why 50/50 co-founder relationships don’t work.
2. Vesting
Use a 4-year vesting with 1-year cliff.
No exceptions.
If someone walks in month 6 and keeps 40% of the company...
You’ve just created a long-term fundraising nightmare.
3. Roles & Responsibilities
Write them down.
Even if it feels obvious now.
Nothing wrecks momentum like overlapping roles and silent resentment.
4. IP Assignment (esp. for deeptech)
Building with patents?
University research?
Proprietary IP?
Make sure all IP lives inside the company, not in your head, your laptop, or your PhD co-founder’s thesis.
No IP assignment = no serious funding.
Now pause here.
Because once this agreement is signed...
You’re not just co-founders anymore.
You’re building a brand.
And this part?
Most people phone it in.
Let’s talk brand. And how most founders get it wrong.
You have 1 chance to look legit in front of investors.
1 chance to signal trust to customers.
And it’s not more features.
Which brings me to my favorite brand agency in climate:
Overstory: Timeless design for Climate startups
They don’t do trends.
They don’t do AI-made logos.
They build brand identities that actually last.
They’ve done magic in the space already. I’m def cheering for them.
If you’re building something in green-tech or sustainability, get on a call with Fabian at Overstory.
Even if you don’t hire them.
Even if you’re not ready.
Even if you just want a second opinion.
👉 Fabian is offering a free 15-min consult for our community.
He’ll help you figure out your next design move. No pressure, no pitch.
Back to the co-founder agreement.
My 3 Favorite Templates
Steal these and adapt them.
TL;DR
Don’t skip the co-founder agreement.
It’s not about trust.
It’s about building something serious, with maturity, and planning scenarios in case shit hits the fan.
And while you’re at it,
Don’t skip the brand either.
This thing you’re building?
It’s got to look the part.
Inside and out.
From the start. Take that free 15min call.
Founder tools that will give you the ultimate unfair advantage:
📌 The Ultimate Investors List of Lists (12,000 VCs, FOs, Angels)
🦄 40 pitch decks that built Unicorns (how Airbnb, Coinbase, Canva got funded)
⚡️ The Ultimate Notion Data Room (all key docs you’ll EVER need)
🥇 The Most Successful Investor Update Template
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Stay tuned! A special new resource is arriving Tuesday for PRO subscribers.
Yoann
