How to write the marketing plan section of a business plan

BusinessPlanHub Editorial Team · Published 23 October 2026

The marketing plan section of a business plan is the part that explains how strangers become paying customers and what each one costs to win. It connects two numbers the reader will otherwise connect for you: the marketing line in your profit and loss forecast, and the customer count behind your revenue. If those two numbers do not explain each other, the section has not done its job.

The SBA’s own guidance puts the brief in one line: describe how you will “attract and retain customers” (checked 9 October 2026). That is the whole job. This guide answers the questions founders actually get stuck on, in the order a lender or investor tends to ask them, and works one of our sample plans through the arithmetic.

What does the marketing section need to show?

Four things, and the last one matters most. Who the customer is, how they will hear about you, what you will spend to reach them, and how many of them that spend produces.

Most marketing sections stop at the first two. They list channels (social media, Google Ads, local partnerships, a website) with no cost beside them and no customer count after them. A list like that reads the same in every plan, so it tells the reader nothing about yours.

What earns credit is the chain: spend leads to enquiries, enquiries lead to customers, customers lead to the revenue in your forecast. The sales and marketing section of our template has the fill-in prompts. This page shows how to make the numbers behind them hold together.

How do you turn a marketing budget into a customer number?

Work channel by channel. For each one, write down what it costs, what the money buys (clicks, leads, introductions, homes reached), what share of those become enquiries, and what share of enquiries become customers. Multiply through and you have an expected customer count you can defend.

The table below is illustrative. Suppose a new home-services business budgets $1,500 a month. The figures are placeholders picked to make the arithmetic easy to follow, not benchmarks; every one of them should be replaced with a quote, a test result or your own history.

Two things make this table useful to a reader. The cost column can be checked, because each figure points to a quote or a rate card. And the assumption column shows where the plan could be wrong, so the reader can test the weakest link instead of distrusting the whole thing.

The conversion steps are the soft part. If you have no history, run a small test before you write the plan. A few hundred dollars of search ads over a month gives you a click cost and an enquiry rate that are yours, which is worth more than any average you could quote.

How do you work out customer acquisition cost for a business plan?

Customer acquisition cost (CAC) is the sales and marketing spend for a period divided by the new customers won in that period. In the table above it is $1,500 ÷ 20, or $75.

The decision that changes the answer is what goes on top of the fraction. Advertising alone gives the flattering figure. Advertising plus the wages of whoever does the selling gives the honest one. Use the second, or show both and say which is which. A reader who works it out the other way and gets a number several times bigger will assume you hid it.

Count new customers only. Repeat orders from last year’s customers did not cost this year’s budget to win, and folding them in makes acquisition look cheaper than it is.

How does the marketing section connect to the profit and loss forecast?

Directly: the total in your marketing section should equal the marketing lines in your P&L, year by year, and the customer count should be the one your revenue forecast is built on. Then the reader can derive cost per customer and gross profit per customer from the forecast and check them against what the marketing section claims.

Our septic tank sample plan shows the sum. The business and its figures are fictional, but the test is the one a reader runs. In year one the septic sample models:

On the full figure, each customer costs about $58 to win and brings about $295 of gross margin on average over the year, so the cost of winning a customer is a small fraction of what that customer brings in. Sales and marketing together come to about 10.5% of revenue.

That looks healthy. It is also exactly where a careful reader slows down, because $7,800 of advertising producing 850 customers is about $9 of advertising each. A number that low is not a strength until it is explained. The plan has to show that most of those customers come from somewhere other than paid advertising: referrals from plumbers and home inspectors, repeat pumping on a maintenance cycle, the sales payroll doing the work. Put that split in the channel table and the low figure becomes credible. Leave it out and it looks like a forecast that forgot to budget for its customers.

What is payback, and how quickly should marketing pay for itself?

Payback is the time it takes a customer’s gross profit to repay what that customer cost to win. Divide CAC by gross profit per order for a one-off sale, or by monthly gross profit for a subscription, and you have it in orders or months.

There is no official standard, but two rules of thumb are widely used, and they should be presented as rules of thumb rather than requirements:

• One-off sales: CAC should be below the gross profit on the first order. If it is not, the plan has to show the repeat business that closes the gap, with a repeat rate you can justify.
• Subscriptions and repeat services: investors often compare lifetime value with CAC and expect lifetime value to be several times larger. Lifetime value rests on a churn assumption, so state the churn and show the ratio at a worse one.

Payback also drives cash. Marketing is paid now and recovered later, so a slow payback means the business needs working capital to fund its own growth. That belongs in the cash flow, which our financial projections guide covers.

What happens to the plan if conversion is lower than you hoped?

CAC rises in proportion. If half as many enquiries become customers, each customer costs twice as much, and either the budget goes up or the customer count goes down. Both change the forecast.

So show it. One short paragraph or a two-row table: the plan at your assumed conversion, and the plan at half of it, with what you would cut or change. A reader who sees you have already tested your weakest assumption has less reason to test it for you. Our guide to what SBA lenders look for covers the supporting assumptions the SBA’s lending rules ask for behind projected revenue, and what investors look for covers how an investor reads a market size built from customer counts.

Where to start

Open your revenue forecast and write down the number of new customers it needs in year one. Divide your year-one sales and marketing total by it. If that cost per customer is higher than the gross profit on a first order, fix the channel mix or the forecast before you write a word of marketing prose.

If you cannot say which channels will produce those customers, or what they will cost, that is a marketing question before it is a writing one. Our marketing consultation works through positioning, channel and budget choices and ends with a written action plan. When the channels are settled and the numbers still will not reconcile with the forecast, that is usually where doing it yourself stops working: the business plan writing service builds the model and the plan together, and the DIY toolkit carries your marketing budget and sales forecast through to the financials as you fill them in.