Guide
Side project with a partner and no company: what to write down
You can start building tonight. You do not need a company yet. But you do need a few things on paper before money, code or customers show up.
Not legal, tax or financial advice. Rules differ by country. Use this to organise your thinking and check anything important with a professional.
Why it matters even for a small project
Without a company, nothing says who owns the code, the domain or the income. In many places two people running a business together can be treated as a partnership by default, which can mean shared rights and shared liability. The details differ, so it is worth a short written agreement.
Write down these six things
- Shares: who gets what share, and whether it vests over time.
- Roles: who does what, and what happens if someone stops.
- Costs: how you split them and who pays which tool. See how to split SaaS costs.
- Accounts: domain, code, hosting, social and ad accounts belong to the project, with at least two admins.
- Code and ideas: work for the project belongs to the project, and anything you bring in is licensed or listed.
- Exit: what happens if someone leaves or you stop. Include a handover period.
When to form a company
Usually when money starts coming in, when you take on customer data, when you hire or when someone wants to invest. A lawyer or accountant in your country can tell you the right form. Carry your written agreement across so the shares you agreed are the starting point.
Keep a record while it is easy
A dated record of who paid what and who controls each account, confirmed by each partner, is cheap to keep and valuable if there is ever a disagreement.
Do it with AI
Get your agreement drafted by interview
Let an AI ask the questions and write the first version.
Act as a startup mentor, not a lawyer. Interview me one question at a time to write a one-page agreement for a side project with a partner and no company yet. Cover shares and vesting, roles, cost split, who owns the domain, code and accounts, income split, and what happens if one of us leaves. Ask which country we are in and flag where local law matters. At the end list three things to ask a lawyer.
Frequently asked questions
Do I need a company to start a side project with a partner?
No, but you need a written agreement about shares, costs, code and accounts. A company becomes useful when money, customers or investors arrive.
What happens if we do not write anything down?
The default rules of your country apply, which may be unclear or unfair to one of you. Writing it down takes about twenty minutes.
Who owns the code in a side project?
Usually the author, unless there is an employment relationship or a written assignment. Say in your agreement that project work belongs to the project.
Can we split income without a company?
Yes, if you agree it in writing, for example in the same ratio as shares after costs. Check local tax rules.
Related
Record shares, costs and who owns each account, and let each partner confirm it.