Business Plan with ChatGPT: How to Write One That Holds Up
Short answer: you can write a business plan with ChatGPT in an afternoon if you do it in the right order. First let it interview you about your offer, customer, prices and costs. Then have it write a lean plan section by section, with every number taken from your answers. Ask it to mark missing data as [SOURCE NEEDED] instead of filling it in, and build the 12-month table yourself from assumptions you can defend. The danger isn’t bad writing; it’s confident numbers the model made up.
Below: what ChatGPT does well in a business plan, the step-by-step method, a prompt you can paste, and the checks to run before anyone else reads it.
Can ChatGPT write a good business plan?
It can write one that reads well. Whether it holds up depends on what you give it, because a language model writes the most likely text, not the true one. Ask “write a business plan for a coffee shop” with no other input and you’ll get a plan for an average coffee shop. Its market sizes and growth rates will sound right and may not be.
| Ask ChatGPT to do | Keep for yourself |
|---|---|
| Interview you and organize the answers | Your prices, costs and margins |
| Write the sections in plain language | Market size and competitor facts, with sources |
| Spot missing parts and weak arguments | The assumptions behind the 12-month numbers |
| Rewrite for a bank, an investor or your team | The decision to go ahead |
The same model works in Claude; the method below doesn’t depend on which one you use.
How do you write a business plan with ChatGPT, step by step?
1. Say who the plan is for
A bank wants to see that you can repay a loan. An investor wants to see how big this can get. A plan for yourself needs to show whether the numbers work at all. Tell the model which reader it’s writing for, because the same facts get ordered and weighted differently for each.
2. Let it interview you before it writes
Paste this first: “Before writing anything, ask me the questions you need to write a lean business plan, about ten, one group at a time.” Answer in your own words. The interview is where the plan’s facts come from, so this is the step not to skip.
3. Write it section by section
A lean plan has these sections: executive summary, problem, customer, offer, market, competition, go-to-market, operations, team, financials, milestones and risks. Ask for one or two sections at a time and correct each before moving on. Corrections made early carry through to the rest, so you fix a wrong price once instead of in six places.
4. Ban invented data
Tell the model: “Use only the numbers I give you. Where a number or a source is missing, write [SOURCE NEEDED] and what kind of source would answer it.” Then look the gaps up yourself in places a bank would accept: official statistics, industry reports, your own sales records.
5. Build the numbers from unit economics
Start small: price per sale, cost per sale, margin, and how many sales a month cover your fixed costs. Ask the model to turn those into a 12-month table and to show the formula for each line. A table you can trace back to four inputs is one you can defend in a meeting; a table full of round growth percentages is not.
6. Read it as the person who will judge it
Ask: “Read this plan as a loan officer. List the five questions you’d ask me and the weakest section.” Fix those, then ask for the version you need: a one-page summary, a pitch outline, or a plain internal plan.
What prompt should you use for a business plan with ChatGPT?
You are helping me write a lean business plan for [business] in [city or market]. The reader is [bank / investor / me]. First ask me about ten questions about the offer, customer, prices, costs and goals, one group at a time, and wait for my answers. Then write the plan in Markdown: executive summary, problem, customer, offer, market, competition, go-to-market, operations, team, financials, milestones, risks. Use only the facts and numbers I give you. Where something is missing, write [SOURCE NEEDED]. Build a 12-month table only from my assumptions, list them under the table and show each formula.
To build prompts like this for other documents, the AI Prompt Generator in the Nexin library does the structure for you. For the parts before the plan, the SWOT analysis and unique selling proposition prompts help you sharpen what the business is.
What should you check before you send it?
- Every number traces back to you or a source. If you can’t say where a figure came from, it’s a guess.
- The market section has real sources. Model-written market sizes are the first thing a reviewer questions.
- The 12-month table adds up. Recalculate two or three lines by hand.
- The risks are real. A plan with no serious risk listed reads as naive to a lender.
- It sounds like you. You’ll be asked about it in person. Cut the phrases you’d never say; humanize AI text lists the usual ones.
FAQ
Is ChatGPT free for writing a business plan?
ChatGPT has a free plan, and so does Claude (is Claude free? covers what it includes). The method above works on either free plan; paid plans mostly give you more usage and longer conversations.
Will a bank accept a business plan written with ChatGPT?
A bank judges the plan, not the tool. What matters is that the numbers are yours, the sources are real and you can explain every line.
How long should a lean business plan be?
Short enough to read in one sitting. Each section can be a few paragraphs; the financial table and its assumptions matter more than the page count.
Can ChatGPT do the financial projections?
It can lay out the table and the formulas from your inputs. It shouldn’t choose the inputs: price, costs, conversion and growth rates have to come from you or from data you can show.
What’s the difference between a business plan and a marketing plan?
A business plan covers the whole business: offer, customer, operations and money. A marketing plan covers how you’ll reach and win customers, and fits inside it.
The same method as a skill in Claude. The Business Plan Writer skill in the Nexin library runs the interview above and writes the lean plan section by section. It marks missing market data [SOURCE NEEDED] and builds the 12-month table only from the assumptions you gave, listed under it. Install it once (how to install a skill in Claude) and say “help me write a business plan”. It comes with Nexin Lite ($14 once, 7-day money-back guarantee) or Nexin Pro ($19 a month, 7 days free). Either plan opens the whole library, including the Marketing Plan Writer. See pricing.