What you’ll be able to do

You’ll end up with a plan that reads like you actually know your numbers, because you will. Not a plan stuffed with guesses dressed up as facts. A proper one, the kind you could hand to a bank manager or a mate putting money in, and they’d nod along instead of asking the question that kills it: where did this number come from?

AI is genuinely good at structuring this stuff and drafting the prose so it doesn’t sound like a ransom note. What it can’t do is know your rent, your supplier costs, or whether your neighbours would actually pay for your thing. That bit’s on you.

Before you start

Get your real numbers together first. I mean actually gather them, not just have a rough idea in your head.

You need: your realistic prices, what you’ll actually charge; your real costs, ingredients, software, rent, whatever applies; and a conversation or two with an actual potential customer, even a rough one. Five people saying “yeah I’d pay a tenner for that” is worth more than any AI-generated market estimate, because the AI is just guessing when it gives you a market size. It has no idea. It’ll sound confident about it too, which is the problem.

If you’re VAT registered, know it. If you’ve got quotes from suppliers, have them to hand. If you’ve priced out a unit of whatever you’re selling, know your margin. Vague inputs get you a vague plan with confident-sounding nonsense filling the gaps, and a bank can smell that from across the room.

Also decide what this plan is actually for. A loan application reads differently to a pitch to a friend with spare cash. Know your audience before you start typing.

Get set up

For most people, ChatGPT or Claude will do this job fine. Both can hold a long conversation, structure a document section by section, and draft prose that doesn’t read like a robot wrote it (mostly). Gemini and Copilot can do similar things, particularly if you’re already inside Google Workspace or Microsoft 365 and want the plan to land straight into a doc.

There’s also LivePlan, which is a paid tool built specifically for business plans, with templates and financial projections baked in. If you want more hand-holding and don’t mind paying for it, it’s worth a look. I’d still say: start with a free assistant first, because you need to understand your own numbers before software templates them for you.

And don’t skip the free stuff. The British Business Bank has a genuinely useful business plan template, and Start Up Loans (part of the same family) has one too. Gov.uk has guidance on what a plan needs to cover. These are free, they’re official, and they’re built by people who’ve seen what banks actually want. Use one as your skeleton, then get the AI to help you flesh it out with your numbers.

What the AI is good at here: organising your thinking into sections, turning bullet points into readable prose, spotting where your logic has a gap. What it’s not good at: knowing your market size, predicting your growth rate, or giving you legal or financial advice. If it tries to hand you a market statistic, stop and ask where it got that from. It didn’t get it anywhere real.

Try it yourself

Here are three prompts that each do a different job. Use them in order, and paste your own real numbers in wherever you see brackets.

First, get the structure sorted before you write a word of content.

I'm writing a business plan for [type of business] to show to [bank/investor/partner]. 
Give me a section-by-section structure I should follow, based on what a UK bank or 
lender would expect to see. Don't fill in any content yet, just the skeleton with a 
one-line note on what goes in each section.

Second, draft a section using your actual numbers, not invented ones.

Using only the numbers I give you, write the "Financial Overview" section of my 
business plan in plain English. My monthly costs are: [list them]. My price per 
unit/service is: [amount]. My expected monthly sales in month one are: [number], 
rising to [number] by month six. Do not add any numbers I haven't given you. If 
something's missing that you'd expect a bank to ask about, tell me instead of 
guessing.

Third, and this is the one people skip: get it to argue with you.

Act as a cautious bank lending manager reviewing this business plan. Read what 
I've given you and tell me: what would you refuse this loan for? What's the 
weakest assumption? What number would you ask me to justify first? Be blunt, 
don't be encouraging.

That last one is the most useful thing you’ll do all day. Most business plans fail not because the writing’s bad, but because nobody stress-tested the assumptions before a real bank did it for them, for free, by saying no.

Keep each section short. A plan that goes on for pages doesn’t look thorough, it looks like nobody edited it. Two or three pages plus financials is often plenty for a small business.

Check the result

Once you’ve got a draft, don’t just read it and nod. Test it.

Check every number against your own source. Go through the plan line by line and ask: did I give the AI this figure, or did it appear from nowhere? If you can’t point to where a number came from, cut it or fix it.

Ask the assistant to list every assumption separately from every fact. Literally prompt it: “list every number in this plan and tell me whether it’s something I gave you or something you inferred.” This will often surface things you didn’t notice, like a growth rate the AI quietly smoothed in to make the story flow.

Read the financials out loud to someone who isn’t you. If your costs and revenue don’t add up in a way a stranger can follow in one read, it needs simplifying, not more words.

Check the tone matches your audience. A bank plan should sound sober and specific. If it reads breezy or salesy, that’s the AI’s drafting instinct showing through, and it needs toning down.

Finally, check nothing in there qualifies as legal or financial advice dressed up as fact. If the AI has told you what structure to incorporate as, or made a claim about tax treatment, verify it separately. It’s not qualified to tell you that, and neither, frankly, is this guide.

If it doesn’t work

A few things go wrong more often than others.

The AI invents a market size or a growth rate. This happens constantly and it will sound completely plausible, phrased with total confidence, a specific-looking percentage and everything. It’s not real unless you gave it a source. Every figure in your plan needs to be traceable to something you can point to: a quote, a customer conversation, an industry report you actually read.

Don’t hand over anything commercially sensitive to a general AI assistant if you’re worried about it being used for training data or seen by anyone else. Check the privacy settings of whichever tool you’re using, most let you turn off chat history being used for training, but read the actual policy rather than assuming. If your plan contains a genuinely secret pricing model or an unfiled patent idea, be cautious about what you paste in.

Never treat the output as legal, financial or tax advice. It isn’t, and no disclaimer buried at the bottom of a chat changes that. If you’re about to sign a loan agreement or register a company, that’s the point to talk to an actual accountant or adviser, not extend the AI conversation.

If the plan comes out too generic, too “any business could be this,” that’s usually because you didn’t feed it enough of your own specifics. Go back to before you start and get more concrete numbers, then redo the draft. The fix is almost always more real input, not a cleverer prompt.

Keep exploring

If you’re still working out what to call the thing before you plan it, there’s a guide on how to get AI to name my business. If you’ve already got customers giving you feedback and want to make sense of it, there’s how to get AI to analyse customer feedback. And if the financial side of this plan needs its own working model rather than just prose, try how to get AI to make a spreadsheet.

Sources and review notes

Review date: 15 September 2026 — every source above was opened and checked against the text on that date.