Do you need a co-founder, or can you start alone?

Whether you need a co-founder is the first real decision of a start-up, and it is often made for the wrong reasons: because everyone says you should have one, or because starting alone feels lonely. This guide looks at what the data says, when a co-founder changes the odds, when it does not, and how to decide for your case.

What does the data say about solo founders?

More people start alone than a few years ago. According to Carta's Solo Founders Report, the share of new start-ups with a single founder rose from 23.7 percent in 2019 to 36.3 percent in the first half of 2025. Better tools, cheaper infrastructure and AI assistants make a first product possible for one person.

Money tells a different story. The same report shows that solo-led companies were about 30 percent of the start-ups founded in 2024 but received only 14.7 percent of the cash raised in priced rounds that year. Investors still back teams far more often. One reason is risk: with one founder, an illness, a burnout or a lost motivation ends the company. Another is judgement: nobody inside the company tells the founder when they are wrong.

Solo founders also hire earlier. Carta found that they bring in a first employee after a median of 399 days, against 480 days for teams. They replace the missing co-founder with staff, which works for skills, but not for shared risk.

When do you need a co-founder?

You need a co-founder when the company depends on something you cannot do and cannot buy soon enough. The usual gaps:

• A skill the first version needs. If the product is software and you cannot build it, you either find a technical co-founder, pay an agency with money you do not have, or wait. A co-founder who can build is the usual answer.
• The other half of the job. Building and selling are two jobs. One person can do both for a while, rarely for years.
• Time. If you can give the company evenings only, a co-founder who is full-time keeps it moving.
• Judgement. Someone who argues with you as an equal, before customers and investors do.
• Resilience. The hard months are easier with someone who carries the same risk. That is not a soft reason; it is why many solo founders stop.

Noam Wasserman, who studied thousands of start-ups for The Founder's Dilemmas, found that most failures of promising companies go back to people problems inside the founding team. He has since clarified the figure: of the venture-backed, high-potential start-ups that failed, about 65 percent failed because of people problems. The lesson cuts both ways. A bad co-founder is worse than none, and a good one is the best risk reduction you can get.

When can you start alone?

You can start alone when you can build and sell the first version yourself, and when you want to. Some companies fit that: a product in your own field, a service you can deliver, a niche where speed and control matter more than scale. Many solo founders in Carta's data are experienced people who have done the job before and know exactly which help to buy.

Starting alone has real advantages. You decide fast. You keep the equity, which means that an exit, even a small one, is yours. You never spend an evening arguing about direction. What you give up is the second opinion and the shared load. If you start alone, build both in on purpose: an advisor who challenges you, a first hire early, a peer group of other founders. For that sparring, the platform Fractionista, for example, lists advisory board members from different industries who work with entrepreneurs and start-ups.

Starting alone is not the same as staying alone. Many founders start solo, prove the idea, and then look for a co-founder with the evidence in hand. That is a strong position: you know what the gap is, and you can show what the company is worth.

How do you decide for your case?

Write down the plan for the next twelve months and mark every part you cannot do yourself. Then ask three questions about each gap:

1. Can I learn it fast enough? A founder can learn to sell. Most cannot learn to build a production system in a year.
2. Can I buy it? Freelancers, agencies and a first hire close many gaps, if there is money and if the gap is not the core of the product.
3. Does this part need an owner? Some tasks can be done by a contractor who delivers and leaves. Others need a person who treats them as their own company and carries them for years. The core product almost always belongs to the second group.

If a gap survives all three questions, you need a co-founder for it, and you now know which kind. That is the brief for your search, and it is a much better brief than "someone technical" or "someone with business sense". Our guide on how to find a co-founder starts from that brief, and the questions to ask a potential co-founder help you check whether a person really fills it.

What should you not do?

• Do not take a co-founder for company. A friend who shares the enthusiasm but no gap costs equity and adds decisions.
• Do not take the first person who says yes. The shortage of co-founders is real, and it tempts people into fast commitments. A trial project of a few weeks shows more than a dozen coffees.
• Do not promise equity before you agree on contributions. Decide what each person brings first; our guide on how to split equity between co-founders shows what should count.
• Do not confuse a co-founder with a first employee. A co-founder shares the risk, the equity and the final decisions. An employee gets a salary and a smaller stake. Both are fine, but they are different deals.

If your answer is "I need one", Cofoundista is built for exactly that step: founders publish a co-founder search with the gap they need to fill, and people who want to join a venture see how well they fit before anyone writes a message. If your answer is "not yet", the open roles still show what founders in Europe look for right now, which is a useful mirror for your own plan.