One-page business plan with assumptions to test

You are a practical small-business advisor. Help me turn my idea into a one-page business plan.

The idea: [DESCRIBE IT IN 2-5 SENTENCES]
Location or market: [CITY, COUNTRY, OR "online"]
Who I think the customer is: [DESCRIPTION]
My resources: [e.g. "€8k savings, evenings and weekends, a van"]
What I already know: [ANY PRICES, COSTS, CUSTOMER CONVERSATIONS OR NUMBERS]
Goal for the first year: [e.g. "replace half my salary", "test demand"]

Write a one-page plan (about 400 words) with these sections:
1. Customer and problem: who has the problem and how they solve it today.
2. Offer: what I sell, and why it is better than the current solution for this customer.
3. Channels: how customers will find and buy it.
4. Revenue model and pricing: how I make money, with a starting price range and the reasoning.
5. Key costs: fixed and variable costs I should expect, using my numbers where I gave them.
6. Simple break-even: how many sales per month cover my costs. Show the arithmetic.
7. Milestones for the first 6 months.

Then list the 5 riskiest assumptions in the plan, with a cheap test for each that I could run in under two weeks (e.g. a landing page, 10 customer calls, a pre-order).

Rules: label any number I did not provide as "ESTIMATE - CHECK". Do not present estimates as market data.

Example (excerpt):
Offer: Weekly delivery of locally baked sourdough to office kitchens, ordered by subscription.

Pricing: €45-60 per office per week (ESTIMATE - CHECK), based on 10 loaves and your cost of €2.10 per loaf.

Break-even: margin per office = (€50 price − €21 bread cost) × 4.3 weeks ≈ €125/month. Fixed costs €900/month ÷ €125 ≈ 7.2, so 8 office subscriptions.

Riskiest assumption: offices will pay for bread, not just coffee.
Test: offer a free first week to 10 offices and count how many convert to paid.

When to use it

Use this prompt when you have a business idea and want to know whether it holds together before you spend serious money or time on it. It suits side projects, small local businesses, freelance services and early-stage startups. A one-page plan is also a useful document to share with a partner, a mentor or a bank adviser as a starting point for a conversation.

How to customize it

• [THE IDEA] should be concrete enough that someone else could explain it back to you.
• [LOCATION OR MARKET] affects prices, costs and regulations. A café in Milan and an online course have very different economics.
• [WHO I THINK THE CUSTOMER IS] is phrased as a belief on purpose. The plan will treat it as an assumption to test.
• [MY RESOURCES] keeps the plan realistic about time and money.
• [WHAT I ALREADY KNOW] is where real numbers go. The more you provide, the fewer estimates the plan needs.

Why it works

A one-page format forces clarity. If you cannot explain the customer, the offer and how you make money in a few lines, the idea is not ready yet. The sections follow the logic most lean planning methods share: who has the problem, what you offer, how you reach them and whether the numbers work.

The break-even calculation with visible arithmetic is a quick reality check, and showing the working lets you spot errors; models can make mistakes in arithmetic, so recheck it yourself or in a spreadsheet. Labelling unprovided numbers as estimates stops guesses from looking like research. The riskiest assumptions and cheap tests turn the plan into a short learning programme, which is usually the most valuable next step for an early idea.

Tips and variations

• After running your tests, paste the results and ask: “Update the plan and the assumptions based on what I learned.”
• Ask for a list of permits, insurance or registrations to check in your country, then confirm them with official sources.
• Use the SWOT analysis prompt once the plan is firmer.
• If you plan to sell online, our AI guide for small online shops has practical next steps.