Guide · EasyCofounder
How to split equity between co-founders
Splitting equity between partners is both a financial and a human decision. This guide gives general pointers to help you start the conversation calmly. It does not replace advice from a lawyer or accountant on your own situation.
Updated on 5 min readBy the EasyCofounder team
In short
There is no universal rule for splitting equity between co-founders: the split should reflect each person’s role, future commitment, contributions already made and how scarce their skills are, and everyone should see it as fair. Many teams combine it with vesting (shares earned progressively) and formalise it in a shareholders’ agreement drafted with a professional.
Contents
- What principles should guide the equity split between co-founders?
- Which criteria should you take into account?
- What does equity-split reasoning look like?
- What are vesting and a cliff?
- How do you plan for future partners and employees?
- Which mistakes should you avoid?
- How should partners hold the conversation?
- Frequently asked questions
- Glossary
- About this guide
What principles should guide the equity split between co-founders?
A startup’s equity mainly rewards future contribution: most of the value is still to be built. A fair split is therefore one that reflects each person’s role and commitment over the coming years, and that all partners consider equitable.
A split that causes frustration from day one weakens the team, whatever the exact percentages. The goal is not to “win” the negotiation, but for everyone to stay motivated for the long haul.
Which criteria should you take into account?
| Criterion | Questions to ask |
|---|---|
| Role and responsibilities | Who owns what over the coming years? Who makes decisions in which area? |
| Commitment | Full-time or part-time? Start date? Giving up a salary? |
| Contributions made | Idea, prototype, first customers, money invested, intellectual property contributed? |
| Scarcity of skills | Is the skill critical and hard to find for this project? |
| Risk taken | Who is leaving a stable job, who is investing their savings? |
The idea alone generally weighs less than execution: a partner who brings the idea but is barely involved should not, in principle, keep a majority over partners who will build the company day to day.
What does equity-split reasoning look like?
The following examples illustrate one way of reasoning. They are not a recommendation: every situation is different.
A developer and a salesperson launch a software product together, both full-time from day one, with no significant financial contribution from either. They opt for a near-equal split and include a mechanism in their agreement for resolving disagreements.
A founder has been working alone for a year and has signed their first customers. A technical partner joins full-time to rebuild the product. The split takes into account the ground already covered, while giving the new partner a stake large enough to commit for the long term.
An industry expert contributes their network and a few hours a week without leaving their job. The full-time partners hold the vast majority of the equity; the expert receives a smaller stake, possibly earned progressively.
What are vesting and a cliff?
Vesting is a mechanism for earning shares progressively: each partner “earns” their shares over the time they spend in the company. The cliff is a minimum period before which no shares vest. If a partner leaves early, they keep only part of their shares, which protects those who stay.
- 1The partners agree on a total vesting period.
- 2They set a minimum period (cliff) before anything vests.
- 3After that, shares vest progressively, for example monthly or quarterly.
- 4The agreement sets out what happens to unvested shares if someone leaves.
How do you plan for future partners and employees?
Equity is not shared only among founders: investors, key employees or future partners may come in. Planning for these changes avoids having to renegotiate in a hurry.
- Set out in the agreement the rules for admitting new partners.
- Think early about incentives for your first employees (for example a stock option plan, whose rules and tax treatment vary from country to country).
- Bear in mind that each funding round reduces everyone’s percentage (dilution).
Which mistakes should you avoid?
- Don’t split equally by reflex, just to avoid the conversation.
- Don’t lock in the split without a vesting mechanism.
- Don’t forget to leave room for future partners and early employees.
- Don’t postpone the conversation until the stakes are higher.
- Don’t sign before a professional has reviewed the articles of association and the shareholders’ agreement.
To find the right partners before discussing equity: the guide to finding a co-founder. To write down the rules: the shareholders’ agreement essentials.
How should partners hold the conversation?
How you discuss matters as much as the outcome. A simple method helps keep the conversation constructive:
- 1Each person prepares their own answers to the criteria (role, commitment, contributions, risk).
- 2The partners compare their answers and explain the differences without trying to “negotiate”.
- 3They agree on a proposed split and on the vesting mechanism.
- 4They take a few days to reflect before confirming.
- 5They have a professional translate the agreement into the articles of association and the shareholders’ agreement.
Frequently asked questions
Should two co-founders split equity 50/50?
An equal split can work if roles, commitment and contributions are genuinely comparable. It can, however, make decision-making harder in case of disagreement, so the shareholders’ agreement should set out how deadlocks are resolved.
What is vesting for a co-founder?
It means earning your shares progressively over the time you spend in the company, often with a minimum period (cliff). It protects the project if a partner leaves early.
Should the person who had the idea hold the majority?
Not necessarily. The idea has value, but success depends above all on execution. The split usually gives more weight to roles and future commitment than to where the idea came from.
Can the equity split be changed later?
Yes, for example when a new partner joins or during a funding round, but this requires the partners’ agreement and legal formalities. It is best to plan for these situations in the shareholders’ agreement.
Who should I consult about splitting equity?
A corporate lawyer or an accountant can help you translate your agreements into the articles of association and the shareholders’ agreement, and assess their legal and tax consequences in your country.
Does vesting also apply to the founder who started the project?
Often, yes: applying the same rules to all co-founders reinforces a sense of fairness and protects everyone if a partner leaves early. The terms are discussed and formalised with a professional.
Glossary
- Share capital
- The total contributions made by the partners to the company, divided into shares.
- Dilution
- The drop in the percentage each partner holds when new shares are issued.
- Vesting
- Earning shares progressively over the time spent in the company.
- Cliff
- The minimum period before which no shares subject to vesting are earned.
Find my partners
Meet co-founders ready to commit
Further reading
- Find a co-founderHow to find a co-founder for your startup: CTO, CEO and COO profiles, where to look, how to choose, equity and the mistakes to avoid.
- Shareholders’ agreementShareholders’ agreement: what it is for, how it differs from the articles of association, common clauses between co-founders and when to sign it.
- Find a business partnerEntrepreneur looking for a business partner? Clarify what you need, where to look, how to choose a partner and how to secure the partnership.
- Find a technical co-founderFind a technical co-founder (startup CTO): the CTO co-founder’s role, preparing your project, where to look and how to assess them if you can’t code.
About this guide
This guide was written by the EasyCofounder team — a platform that connects founders, talents and startups (a service by IRPEA) — and was last updated on November 4, 2026. It draws on common startup practice and on the questions our members ask.
It provides general guidance and is not legal, tax or financial advice. For your own situation, consult a qualified professional (lawyer, accountant) and the official resources available in your country.