How to write a business plan.

A good business plan is a thinking tool first and a fundraising document second. Writing it forces you to make decisions: who exactly you sell to, how you reach them, what it costs and what you will do if it does not work.

Start lean

Start with a one-page Lean Canvas. Expand it into a full plan only when you need one, for example for investors, a bank, a grant application or SEIS/EIS advance assurance.

What to include

1. Executive summary. One page: the problem, your solution, the market, traction, the team and what you need. Write it last.
2. The problem and the customer. Who has the problem, evidence that they care, and your ideal customer profile.
3. The solution. What the product does today, what it will do next, and why it is better than the alternatives.
4. Market opportunity. TAM, SAM and SOM, calculated bottom-up, with sources.
5. Competition. Direct competitors, substitutes and doing nothing. Be honest about their strengths.
6. Go-to-market. Channels, pricing, the sales process and the cost of acquiring a customer.
7. Operations. How the product is built, delivered and supported, including key partners and suppliers.
8. Team and organisation. Who does what now, who you need next, and how you will resource it.
9. Milestones. What you will achieve in the next 6, 12 and 24 months, and the evidence that will prove it.
10. Financials. Profit and loss, cash flow and balance sheet forecasts, with assumptions.
11. Risks. The biggest risks and what you are doing about each one.
12. Funding. How much you need, from whom, and what it is for.

How long?

For most tech startups, 10 to 20 pages plus the financial model is enough. Length does not impress anyone; clear evidence does.

Keep it alive

• Review it every quarter against what actually happened.
• Update the assumptions when the evidence changes, and note why.
• Share the milestones with your team, so everyone knows what success looks like.