Business plan — practical guide
How to Write a Business Plan That Changes Decisions
A business plan earns its keep only when it changes a decision, yours, a lender's or an investor's, so write the parts that drive that decision first and treat the rest as appendix.
Most founders who search for how to write a business plan download a 30-page template and stall somewhere around page four. The template isn't wrong. It's just ordered for a reader who has already said yes. In practice a plan gets read by three kinds of people: you, deciding whether to quit a job or sign a lease; a lender, deciding whether you can repay; and an investor, deciding whether this can get big. Each reads for a handful of answers and skims everything else.
This guide takes a decision-first approach: a one-page plan you can write in an evening, the sections that actually move a lender or an investor, financials that survive scrutiny, and how to keep the plan useful once reality starts disagreeing with it. It will.
What a business plan is actually for
Before you write a word, name the decision. Should I open a second location? Will the bank lend me the money for new equipment? Can I leave my job in six months? A plan built around a real decision has a natural shape: the assumptions that decision rests on, the evidence you have for each one, and what you would do if an assumption turns out to be wrong.
The US Small Business Administration describes two formats. A traditional plan can run to dozens of pages, moving from executive summary and market analysis through to funding request, financial projections and an appendix, and the SBA positions it for founders seeking money from traditional lenders or investors. A lean startup plan is typically one page and can take about an hour, though the SBA notes some lenders and investors will ask for more. In the UK, GOV.UK points founders to free business plan templates from The King's Trust and the Start Up Loans website. Pick the template your reader expects, but decide the content before you open it.
Write the one-page business plan first
Your one-page version needs seven lines. The customer, described narrowly enough to find them: independent dental practices within 40 minutes of your office, not SMEs. The problem, in the customer's own words. Your offer and its price. The one or two channels you will actually use to reach buyers. What it costs you to deliver one unit or serve one client. How much cash you need to reach the point where revenue covers costs, and roughly when. And the three assumptions that would sink the business if they were wrong.
That last line is the most valuable thing you will write. For a café it might be foot traffic at the chosen site, the average ticket, and rent as a share of sales. For a B2B service it might be how many conversations it takes to win one client, the monthly fee they will accept, and how long they stay. Once those are on paper, your next month has an agenda: go and test them.
Show the page to someone who knows the industry and will tell you the truth. If it holds up, expand it. If it doesn't, thirty pages won't rescue it.
The sections of a small business plan that lenders and investors read
A bank is underwriting repayment. It reads the financial projections, especially the cash flow forecast and whether cash covers loan payments with room to spare, the funding request (how much, for what, and how much of your own money is in), and management experience: have you run something like this before? A market section helps only insofar as it makes your revenue forecast believable.
An equity investor reads for size and speed. Sequoia's widely used outline runs from company purpose, problem, solution and why now, through market potential, competition, business model and team, to financials and a five-year vision. The weight falls on why the market can be big, why this moment, and why this team wins. At the earliest stage, evidence that customers want the thing matters far more than a detailed operating plan.
For you, the sections that matter are unit economics and cash. If the plan doesn't tell you how many customers you need each month to cover costs, and how many months you can survive if that takes twice as long, it is decoration.
Business plan financials without the fantasy
Build revenue from the bottom up. Capturing 1% of a huge market tells a reader nothing. Two salespeople, each running 15 demos a month, closing one in five at a set monthly fee, can be checked and argued with, which is the point. Lay out the drivers so anyone can change one and see what happens.
Then build three cases: expected, slow (sales at half the pace), and bad (slow plus a cost overrun). Lenders are reassured by a plan that survives the slow case, and you learn how much money you really need. Keep every assumption on its own tab with a note on where it came from: a supplier quote, a competitor's published price, the conversion rate from your pilot. Labelled guesses are fine. Disguised ones are not.
How real companies' early plans differed from what happened
Uber's first pitch deck from late 2008, which co-founder Garrett Camp later published, described a premium black-car service in a limited set of US cities, with the company owning vehicles and employing drivers under a membership model. The business that actually grew let independent drivers use their own cars. The problem in the plan survived; the solution did not.
Meesho in India went through several reinventions: a local fashion app that failed, a tool for WhatsApp resellers that came from watching how people actually sold, and later a move to a consumer shopping app. The principle behind those turns, as the WOW Mentor teardown frames it, was to be rigid on the problem and flexible on the solution.
Treat your own plan the same way. Write it so you notice quickly when an assumption breaks, and review it monthly against actual numbers. The related WOW Mentor briefings on Meesho, on finding your first customers and on the lean startup debate go deeper into these turns; they are English audio with a full transcript.
Checklist for today
- 1.Write down the single decision this plan must support and who else will read it.
- 2.Draft the one-page plan, including the three assumptions that would sink the business.
- 3.Build a bottom-up revenue model with visible drivers, plus a slow case and a bad case.
- 4.Match the format to the reader: a traditional plan for a bank loan, a tight deck and model for equity investors.
- 5.Book a monthly review to compare actual results with the plan and rewrite any assumption that broke.
Related briefings
English audio with a full transcript.
Frequently asked questions
How long should a business plan be?
As long as your reader needs and no longer. A one-page lean plan is enough to guide your own decisions. The SBA notes a traditional plan can run to dozens of pages, and a bank may want that level of detail for a loan, while investors usually ask for a deck and a financial model first.
Do I need a business plan if I'm not raising money?
You don't need a formal document, but you do need the thinking behind it: who the customer is, what one sale costs you, and how much cash you need before revenue covers costs. The one-page version gets you there in an evening and gives you a list of assumptions to test.
Should I use a business plan template?
Templates help with structure, and free ones exist: the SBA outlines both the traditional and lean formats, and GOV.UK links to templates from The King's Trust and Start Up Loans. Just don't let a template set your priorities. Fill in the sections your reader decides on first, and keep the rest short.
How often should I update my business plan?
Compare it with actual results every month in the first year and rewrite an assumption as soon as it proves wrong. A fuller rewrite makes sense before any new funding request or big commitment such as a lease or a key hire.