What Should My Co-Founder Agreement Say Before We Raise Money?
“We’ve been friends for years. We don’t need a formal agreement.” That mindset has contributed to more startup breakdowns than many founders expect. When a co-founder exits before the raise, or stops pulling their weight six months in, the question isn’t about the friendship. It’s about who owns what and whether investors will fund a company with that hanging over it.
It is best to put the agreement in place before you build. Investors will ask for it.
What a Co-Founder Agreement Actually Covers
A co-founder agreement is not a formality. It is the legal structure that helps protect the company and everyone involved if things go sideways. Here is what it must address:
Equity Split and Vesting Schedule
Nearly 46% of two-founder startups use a 50/50 equity split, up from 31.5% in 2015. Equal splits are common and can work. What cannot work is an undocumented split with no vesting behind it. The standard structure is:
- 4-year vesting with a 1-year cliff
- No equity vests in year one
- After the cliff, equity vests monthly or quarterly for the remaining 3 years
Without vesting, a co-founder who leaves after 6 months keeps 100% of their equity stake. This is difficult to fix after the fact. Investors will flag it immediately.
Roles, Decision-Making, and Voting Rights
Who controls product decisions? Who has authority to sign contracts? What happens when co-founders disagree on a major call? These questions need written answers before the pressure hits. Undefined authority can create deadlock at critical moments.
IP Assignment to the Company
Every founder must assign their intellectual property to the company. This is critical. Without a signed IP assignment, the code one co-founder wrote before formation may legally belong to that person, not the company. Investors run IP diligence. Any gap here can delay or jeopardize a deal.
Buyout Mechanics
What happens if a co-founder wants out, or has to leave? The agreement should define how their equity is valued and whether the company or remaining co-founders have the right to repurchase unvested shares. Without this, departures can create cap table complications.
Common Founder Mistakes
Mistake #1: Relying on a Verbal Agreement
Founders agree on equity split and roles in a conversation and assume that’s enough. It may not be enforceable. When the relationship breaks down, there is nothing to point to. The lack of documentation becomes a legal problem and a fundraising blocker. It is best to document everything early; ideally before significant work begins.
Mistake #2: Skipping Vesting Because It Feels Awkward
This is the most common and most damaging mistake. Founders avoid the vesting conversation because it implies distrust. But vesting is not about distrust. It protects both parties. Without it:
- A departing co-founder keeps equity they did not earn
- The cap table becomes a red flag for investors
- There may be limited legal mechanisms to reclaim that equity
Investors expect vesting to be in place before they fund. Missing it signals governance risk and slows due diligence.
Mistake #3: Leaving Out the IP Assignment Clause
Founders focus on equity and skip the IP assignment. The result is that each founder personally owns whatever they built before the company was formally structured. This is a deal-killer in due diligence. Every co-founder agreement must include a full IP assignment to the company, covering past and future work.
10-Minute Self-Check
☐ Is the equity split documented in a signed legal agreement?
☐ Does the agreement include a 4-year vesting schedule with a 1-year cliff?
☐ Does each co-founder have a defined role with clear decision-making authority?
☐ Has every co-founder signed an IP assignment transferring all work to the company?
☐ Does the agreement include buyout mechanics for a departing co-founder?
☐ Have you had an attorney review the agreement before the raise?
If you are missing any of these, it is worth addressing them now. Investors will surface every gap during diligence.
Bottom Line
A handshake deal works until it doesn’t. When it fails, it fails at the worst moment: during a raise, during a conflict, or when someone walks out. The co-founder agreement is the structure that keeps the company intact when things get hard.
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Sources Used
- Y Combinator, “How to Split Equity Among Co-Founders” — https://www.ycombinator.com/library/5x-how-to-split-equity-among-co-founders
- Carta, “Founder Shares: Key Characteristics and Structures” — https://carta.com/learn/startups/equity-management/founder-shares/
- Lazo, “Founder Vesting Agreement: Why Your Startup Needs One from Day One” — https://www.lazo.us/blog/founder-vesting-agreement