How to Raise Money With Only a Prototype

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Founders often believe they need a finished product to raise money, and that they need money to finish the product. Pre-seed and early seed investors resolve this every day: they fund teams with a prototype and evidence, not with a launched product. This post explains what a prototype needs to do in a fundraising process, what to put alongside it, and how to run the process.

What does a prototype prove, and what does it not?

The right-hand column is what your evidence must cover. A prototype alone is a demo. A prototype plus twenty interviews, three hundred sign-ups and two signed letters of intent is a fundable company.

What kind of prototype do you need?

• A clickable prototype built in a design tool, showing the real screens and the core journey end to end. This is the standard for pre-seed. It costs $5,000 to $25,000 (€4,500 to €22,000, £3,500 to £18,000) from a professional team and takes two to four weeks. It doubles as the specification for the build.
• A functional prototype with a working backend for one flow, real data and perhaps one integration. Stronger, especially for products where the technology is the risk. Costs more and takes longer, and it can become the first slice of the real product.
• A concierge version, where you deliver the service by hand to a handful of paying customers. Not a prototype in the software sense, and often the most convincing evidence of all. Our guide to validation before code explains it.

Choose based on where the risk sits. If investors will doubt demand, spend on evidence. If they will doubt feasibility, spend on a functional prototype.

What evidence should sit beside it?

1. Customer interviews. Twenty or more, summarised: who, what problem, what they do now, what they said they would pay. Quotes in their words.
2. A waiting list from strangers. Sign-ups from paid or organic traffic, with the conversion rate and the cost per sign-up if you ran ads.
3. Letters of intent or pilot agreements. For business products, a signed page from a prospective customer saying they will pilot or buy at a stated price when it exists. Non-binding is fine. Specific is essential.
4. Pre-sales or deposits. Money from people you did not know. Small amounts are still the strongest signal you can show.
5. A budget and a plan. What the round buys: the scoped first release, its cost and timeline, and the milestones it will hit. A fixed-price quote from a credible team makes this concrete.

Who invests at this stage?

• Friends, family and angels. The most common first money. Angels in your industry bring introductions as well as cheques.
• Accelerators. Small investment plus a programme and a network, in exchange for equity. Good for first-time founders who need structure and introductions.
• Pre-seed and seed funds. Increasingly willing to invest pre-product when the team and evidence are strong.
• Grants and competitions. Non-dilutive and slow. Worth pursuing in parallel, never as the only plan.
• Development partners who invest. Some, including 7L, invest in selected ventures or offer flexible payment tied to milestones. This reduces the amount you need to raise and signals that a technical team believes in the product.

How do you run the process?

1. Build the list. Forty to sixty investors who have backed companies at your stage and in your space. Warm introductions convert far better than cold emails, so map who can introduce you.
2. Prepare three things. A short deck, the prototype, and a one-page summary of the evidence. The deck tells the story, the prototype makes it real, the evidence makes it credible.
3. Batch the conversations. Run the first meetings within two or three weeks of each other so that interest builds at the same time. A process that drags for months signals weakness.
4. Demo the prototype yourself. Walk through the core journey in under three minutes. Do not narrate every screen. Show the moment of value.
5. Answer the technical question before it is asked. Who will build it, what it will cost, how long, and what you own. A named partner with a fixed quote and an ownership agreement closes this in one slide. See what investors want to see in your tech.
6. Ask for a specific amount for a specific plan. "We are raising $300,000 (€260,000, £220,000) to build and launch the first release, acquire the first five hundred customers and reach the metrics for a seed round in twelve months."

What mistakes cost founders the round?

• A prototype that shows every feature instead of the core journey. Investors want focus.
• Evidence from friends. Investors can tell.
• No answer to "who builds it and what does it cost". This is the most common gap for non-technical founders and the easiest to close.
• Raising too little to reach the next milestone, which means raising again from weakness.
• Spending the round on features rather than on learning whether customers come back.