50 questions to ask a potential co-founder

Aim for specifics from their past, not hypotheticals about their character.

• Tell me about the last time you were genuinely angry at a colleague. What did you do in the following 48 hours?
• When we disagree and neither of us convinces the other, what should happen?
• Do you get louder or quieter when a conversation gets tense?
• What does an apology from you look like?
• Who ended your last serious working relationship, and what did they say about you on the way out?
• When I've upset you, will you tell me that day, that week, or never?
• What's a criticism of you that you've heard more than once?
• How do you want me to raise something you're doing badly?
• Have you ever stopped speaking to someone you worked with?

Write the answers down. Verbal agreements here evaporate exactly when you need them.

• Which decisions are yours alone, which are mine, and which are both?
• If we're deadlocked on a hire, who breaks the tie?
• What spend amount requires both of us to agree?
• Who is CEO, and what does that actually change day to day?
• How do you feel about being overruled in front of the team?
• If an investor prefers dealing with one of us, how do we handle it?
• What would make you go around me rather than through me?
• Which single decision would you refuse to compromise on?

If any of these feel premature, that discomfort is the reason to ask now.

• What split do you think is fair, and what is that based on?
• Should equity reflect past work, future work, or risk taken?
• Are we vesting, over how long, and with what cliff?
• What happens to equity if one of us leaves in month six?
• How many months can you personally survive with no salary?
• What salary do you need for this to be sustainable for you?
• Are you keeping consulting or contract work? How much?
• What would we do if one of us needed to take money out early?
• How would we handle a small acquisition offer that suits one of us and not the other?
• Do you have debts, dependants, or commitments that change your risk tolerance?

Different answers are fine. Assumed-identical answers are not.

• What outcome would make this a success for you — a number, not an adjective?
• Would you rather own 20% of a large company or 60% of a small one?
• What does a normal working week look like for you in six months?
• What are you not willing to sacrifice for this?
• How long do you give this before you'd call it?
• What would you do if we failed in month nine?
• Is there a job that would make you leave?
• What are you doing this for, honestly — money, proof, curiosity, freedom?

Concrete dilemmas beat abstract values every time.

• Would you exaggerate traction to close a round we badly need?
• A supplier undercharges us by a meaningful amount. What do we do?
• We can cut a corner on privacy for a big customer. Where's your line?
• Would you fire a friend who's underperforming? When?
• How do you handle a customer complaint that's our fault and expensive?
• What's something the industry does routinely that you think is wrong?
• Would you ever pay yourself before paying the team?

The gap between how someone sees themselves and how others do is the most predictive answer on this page.

• What will I find hardest about working with you?
• What do people consistently misread about you?
• When you're stressed, what changes in your behaviour first?
• What part of this company are you worst suited to?
• What did your last manager or partner want you to change?
• What's the least flattering true thing about how you handle pressure?
• If this ends badly, what will your version of the story be?
• How would you know if you were the difficult one?

Asked face to face, these questions reward whoever is better at interviews. People answer the version of themselves they would like to be, and the second person tends to anchor on the first person's answer. The fix is structural: same scenarios, private answers, everyone revealed at the same moment, with a small cost attached to some choices.

Both free games here do that — a scenario trek with two behavioural trust mini-games, and a shared lemonade-stand company where you run eight weeks on shared cash and separate personal accounts. Ten minutes, own phones, no accounts.

What questions should I ask a potential co-founder before starting a company?

Cover six areas: how you each behave in conflict and repair afterwards, who holds which decision rights, equity and personal financial runway, what outcome each of you actually wants, concrete moral trade-offs, and what each of you thinks the other will find hard about them. Ask for past specifics rather than hypotheticals, and write down every answer about money and authority.

How long should the co-founder conversation take?

It isn't one conversation. Do a first pass in an hour, write down the money and decision-rights answers, then revisit them after you have worked together on something real for a few weeks. Answers given before any pressure exists are guesses.

Is there a co-founder questionnaire or test?

Prompt lists like this one help, but they reward well-presented answers. A better format puts the same areas into scenarios that each founder answers privately, then reveals everyone at once so nobody mirrors the group. That is what the two free games on this site do in about ten minutes.

Should we sign a founder agreement before or after these questions?

Ask first, write second, sign third — and include vesting, a cliff, decision rights, and what happens if someone leaves. Reluctance to write down what you have already agreed verbally is itself a strong signal.

If you run an accelerator, a founder community, an angel syndicate or a newsletter, you're welcome to embed the whole list. It's a self-contained widget: no tracking script, no cookies, no attribution required, and it stays up to date on its own.

<iframe src="https://shouldwebecofounders.com/embed/questions?utm_source=embed&utm_medium=widget" width="100%" height="620" style="border:0;max-width:640px" loading="lazy" title="Co-founder questions"></iframe>