Every founder knows the feeling. You're updating your financial model before an investor meeting, revising assumptions after a customer call, or trying to understand what one new hire means for your runway. AI can now do much of that work in minutes.
The temptation is obvious. Why build a model yourself when AI can generate one for you? At Venturelab Trainings for Innosuisse, we see more and more founders integrating AI into financial planning. Used well, it saves time and helps structure complex decisions. Used poorly, it creates something much more dangerous than a bad spreadsheet: confidence without understanding. That's exactly what Innosuisse trainer Diego Seitz has been observing in his workshops.
"Founders seem to delegate too much to AI. It can't develop a winning business plan and it can't replace the need to understand a financial plan in detail."
The strongest financial plans don't come from AI. They come from founders who understand their business well enough to challenge what AI produces.
Performance effects of AI use in a field experiment with 758 consultants.
Source: Dell'Acqua et al. (2026), Harvard Business School and Boston Consulting Group (BCG), "Navigating the Jagged Technological Frontier."
A Financial Model Is a Conversation About Your Business
Many founders see a financial model as something they need because investors ask for one. In reality, it is one of the clearest expressions of how a business is expected to grow. Every assumption tells a story: how customers are acquired, how quickly revenue arrives, how much growth costs, and where the business becomes profitable. That's why financial planning is never just about numbers. It's about understanding how those numbers connect.
AI can organise that information remarkably well. What it cannot do is decide whether your assumptions reflect reality. The founder still has to answer the difficult questions.
Build the Logic Before You Build the Model
One of AI's biggest strengths is speed. One of its biggest risks is skipping steps. Ask AI to generate a financial plan and you'll probably receive something that looks complete. But a strong financial model isn't built in one prompt. It develops one decision at a time.
Diego Seitz recommends exactly that approach.
"Use detailed prompts which include specifics on your business. Break down the work into steps and prompt each step one after the other. Spend time preparing and reviewing."
Every Assumption Needs a Reason
Early-stage financial models are built on assumptions. Investors know that, and founders should too. What matters is whether those assumptions are grounded in reality. This is where many models fall apart. Revenue projections become too ambitious, acquisition costs too optimistic, or hiring plans no longer match expected growth.
According to Diego Seitz, founders should pay particular attention to the inputs that drive the business.
"It's critical to include specifics, especially on your Customer Acquisition Model and your Revenue Model."
Rather than asking AI for "realistic assumptions," founders should explain how their business works and ask AI to test the logic. Better still, ask what evidence would be needed to validate each assumption in the real world. A good financial model doesn't predict the future. It explains why you believe the future might unfold that way.
Make AI Your Toughest Reviewer
Most founders use AI to create. Fewer use it to criticise. That's often where the greatest value lies.
Before presenting a financial model, ask AI to review it like an experienced CFO or a sceptical investor. Which assumptions look weak? What costs are missing? Where is the growth story too optimistic? Which numbers deserve a second look? Diego Seitz actively encourages founders to build this challenge into their process.
"Ask to sense check the model and ask AI to take the perspective of a critical reviewer."
The goal isn't to make the model perfect. It's to uncover the questions before someone else asks them.
Better Questions Lead to Better Decisions
One of Diego Seitz's simplest recommendations may also be his most valuable.
"Ask if AI has questions about your request or needs additional details to produce a better result."
It's an easy habit to adopt, yet it changes the conversation completely. Instead of treating AI as the expert, founders begin treating it as a collaborator. Missing information becomes visible, weak assumptions surface, and the discussion becomes more precise. Founders who ask better questions usually make better decisions. AI doesn't change that principle. It simply makes the feedback loop much faster.
Financial Planning Is Still a Founder Skill
AI can speed up modelling, organise information, and test assumptions. What it cannot do is take responsibility for the decisions behind the numbers. That's still the founder's job. Diego Seitz's perspective reinforces something we see across the Venturelab community: the best founders don't outsource financial thinking. They use AI to deepen it.
The spreadsheet may be generated by AI. The conviction behind it should always belong to the founder.