Why is a business plan important and what should it include?

How do you go from a bright idea to a successful business? Planning. It's easy to imagine successful entrepreneurs played it by ear and got lucky. People often change direction but planning's a crucial part of testing a start-up idea and building a business.

This guide examines why you should write a business plan, what it needs to include and how to use it. We've also highlighted additional resources that can help you go through the process.

Why write a business plan?

Business plans provide accountability. They allow business owners to sense-check what they're doing and why. They provide an opportunity to get ideas out of your head and start working on them.

"Not having to report to anyone is attractive when you start up. As you grow it can be tricky not to have a sounding board. A business plan can be useful for that," said Jonathan Bareham, co-founder of accountancy firm Raeden.

He highlights the role of goal setting in the planning process. Why are you starting a business? Is it because you want a good work-life balance? Do you want to make an environmental impact? It's likely a combination of factors. Writing down your motivation provides a reference for big decisions and makes sure you don't lose focus.

Business plans help explain what you're doing to other people. The process of writing everything down makes sure you can answer key questions about what you're doing.

Hiring people, opening a premise or buying equipment requires significant investment. Planning and justifying what you're going to spend is important. Sharing them externally helps reassure partners, whether you're looking to borrow money or win over a mentor.

What basic things should a business plan include?

Whatever format and length you decide on there are several common topics to cover in a business plan. Bareham outlines five points to include:

• A summary of what you're going to do

• Details of the market you're going into

• What you have that other businesses don't (your unfair advantage)

• A cash-flow forecast

• Personnel needed

Business owners need to think about the strengths and weaknesses they have, he added. Be honest and make sure you identify where you will need help.

Your cash-flow forecast is crucial. It shows the money coming into your business from customers and what you're spending. This includes costs like buying raw materials, office space, marketing and paying employees. This plan will evolve into a document you look at regularly when the business is up and running.

Enterprise Nation founder Emma Jones compares having a business plan to a route map and uses the acronym 'I'm off' as a memory aid on what to include:

• Idea

• Market

• Operations: What kit do you need?

• Finances

• Friends: A support network

You can tailor your business plans to specific audiences and we'll go into the main formats in the next section.

Watch this detailed video with Enterprise Nation adviser and accountant Jonathan Bareham sharing tips on business plans, cash flow, accounts and more.

What business plan format should I use?

There are several formats you can use to create a business plan. It's important to pick the one that's right for your situation. The key considerations are what you know so far and how you're going to use the plan.

You'll generally cover the sections we outlined in the section above but the amount of detail can vary.

If the plan's for the benefit of the business owner you need to think about how much you can know at this point. There are lots of assumptions around sales and costs that you won't know until they're tested. This will limit the level of detail you can include.

The audience is important too. You could write a five-page summary if the business plans just for you. If the business plan's for raising investment or applying for a loan it's going to require more detail and might be 15-20 pages long.

Organisations like the Prince's Trust and Start Up Loans, which offer start-up funding, have templates that they prefer or require applicants to fill out.

David Abrahamovitch, founder and CEO of London café-bar and restaurant company GRIND, told Enterprise Nation that his founding team didn't create a business plan until they needed to borrow money. He believes a formal business plan doesn't provide much value at the concept stage.

"Business plans absolutely have their place but I see people who are spending months writing a business plan. They're worried about who's going to copy their idea about trademarks. All of these things are important, but at the moment you don't have a business. You don't have a brand to protect. You're worried about the wrong things.

"You have to get to the minimum viable form of that business as quickly as possible and just test it."

Abrahamovitch added that things like pop-up stores and online tools mean the barriers to entry are lower than ever, reducing the risk of testing an idea.

What a traditional business plan looks like

What we're calling 'traditional business plans' are A4 documents that cover the key elements of your business. These include five main elements:

• The executive summary: Summarise the main points of your business plan. Showcase what you're doing and sell your vision to the reader.

• Opportunity analysis: Describe the business opportunity. Look at the size of the market, customer segments, competitors and the key trends.

• Marketing: Highlight the key messages you want to communicate to customers and detail the channels you will use to reach them (telemarketing, social media etc.). Provide an idea of cost for this activity and, if possible, the level of business you expect to generate.

• Logistics: Plan where and how you are going to operate your business. Include plans for manufacturing, transportation, office costs, staff needed etc.

• Finance: Make sure that you detail all your associated costs - both your estimated start-up costs as well as your running costs. Include a cash-flow forecast that shows how your business will become sustainable.

Additional information like the founders' CVs can be included in your appendix. This often depends on what evidence your audience requires and may not be relevant for a document that's used internally.

Presentation is important because it provides credibility. Think about adding company logos, a cover page and other touches that make the document look professional.

Abrahamovitch said writing a business plan is useful to examine what's working, how much energy things take up and the margin of different products when you've tested ideas.

"Distill that down into its simplest form and put that in a business plan," he said. "Talk about how you're going to scale it. That's where it really adds value."

The lean canvas model

The length of traditional business plans can be intimidating. You may also lack the information to complete the document if you haven't started trading yet.

Lean canvas and business model canvas allow you to create a business plan on a single page. The structure examines whether a business idea is viable. The nine boxes capture entrepreneurs' key assumptions, covering topics like metrics and marketing channels.

Lean canvas is designed to provide a snapshot of your idea and challenge the assumptions you've made. It's not meant to be perfect. The inventor of lean canvas model suggests taking 20 minutes to fill everything out.

Test your assumptions through research

Launching and growing a small business is really exciting because you don't know what's going to happen. However, writing a business plan can be daunting as there are so many things you don't know yet.

Make phone calls and search the internet to strengthen your assumptions. It's possible to find information on standard services like accountants, renting desks or buying raw materials.

There are other aspects that are more difficult to predict. Projecting sales, for example, is one of the trickiest parts of forecasting. You love your product but will customers flock to the business?

One opportunity to solve this problem is to do a small amount of test trading. Paying for a market stall may cost you a thousand pounds after you pay for the stock and a location. But the investment may pay dividends if it gives you a reality check on what customers are willing to pay and how popular your offering is. What's the least you can spend to learn the most?

Research competitors offerings too. What are people paying for related products?

Service-based business can have the opportunity to trial their offering part-time. Perhaps you can take on a client while still working your day job.

Make sure you justify any forecasts in your business plan and provide a logical explanation of how you came to your conclusions.

Will a business plan guarantee success?

No. But business plans will help crystallise your goals and test your assumptions. The framework is really useful to develop ideas, particularly if they've been rattling around in your head for some time.

Make sure you return to your business plan regularly. Reinforcing your original goals will help keep you on track. Forecasting is a skill. Check your projections against performance and try to figure out what assumptions were correct and where there were issues.

The way you use business plans will evolve over time. Filling in a lean canvas might work if you have an idea and haven't started working on it yet. Eventually, you might need to create a business plan to land investment or it can provide an opportunity to reassess what you do.

Access support to start your business

Visit the StartUp UK hub for resources that give you the education and inspiration to get started on your entrepreneurial journey.