How to Write Business Plan for Existing Businesses

I consider “business planning for existing businesses” the topic we least talk about. We often associate business planning with startups, but no one talks about how established businesses need planning, too—maybe more than startups do.

I see this firsthand in our consulting work. We get at least a dozen calls every month from business owners who've been running their companies for years, asking for help with their business plans.

The most common situations I hear about are:

• We're thinking of adding a new product line, but we're not sure how to approach it.
• Our financial projections are way off from where we want to be
• We need to update our plan because we're going after funding again
• We're considering a major pivot and need to think it through

Today, in this article, I’ll provide a few quick tips to help you write or update your business plan for your existing business.

There’s no secret recipe or something, just the process we follow at PlanGrowLab when planning for an established business.

Business plan for an established business vs. a new one

Before we get into the nitty-gritties, let’s compare and understand how processes change for a new and established business:

How to write a business plan for an established business?

Considering we have two types of readers (writing a plan for the first time and updating the existing version), we need to move ahead in a way that makes sense to both kinds.

Those updating an existing business plan follow the same process as a first-timer would; the only change here is that you already have an existing version to work with.

So, what you’ll do is make changes to your existing plan as we move forward. Makes sense? Let’s start.

1)  Start with the company overview

We’ll start writing your business plan with the company overview. Chronologically, it’s the 2nd section, but since the executive summary is often written last, we’ll start with the company overview.

Your company overview is a crucial aspect of your business plan as it clearly explains what your business does, its mission, its vision, and the markets it serves.

The aim of including a company description in an existing business plan is to help stakeholders understand your company’s evolution and its strategic relevance in the marketplace today.

A well-articulated company overview can also reinforce your business's credibility and help foster trust among new investors and partners.

You can follow the table mentioned below to structure your company overview section.

If you’re updating the existing version

Make sure your company name reflects any recent rebranding or identity changes. Include updates to your legal structure, new locations, or address changes, and be sure to highlight your recent achievements, growth milestones, or any important developments.

2) Include company’s description

A company’s description is a crucial aspect of a business plan as it clearly explains what your business does, its mission, its vision, and the markets it serves.

The aim of including a company’s description in an existing business plan is to help stakeholders understand your company’s evolution and its strategic relevance in the marketplace today.

A well-articulated company description can also reinforce your business's credibility and help foster trust among new investors and partners.

Presenting the information in a table format can help stakeholders quickly grasp your company’s description.

You can use the following table to structure your company’s description clearly and concisely.

3) Inform about your product and services

Once your company overview is locked, it’s time to talk about what you actually offer.

This section of your business plan should clearly explain what you sell, how it works, and why it is important. For an established business, it’s not just about listing features; it’s about showing how your product or service has adapted over time. That’s what investors and internal stakeholders care about.

In our work with founders, we’ve noticed a pattern. The product gets described, but the thinking behind it doesn’t. No trends, no feedback, no changes. And that’s what makes the section feel thin.

Here’s what we recommend including:

• A quick explanation of your core products or services
• How those offerings solve specific problems
• Unique elements (tech, process, packaging, pricing, etc.)
• Evolution over time: What’s changed, and why
• Current market trends that shape customer demand
• Where your offering still needs work
• Planned updates or improvements

Apart from being useful for funding, it also gives your own team clarity on where you’re strong, and where you’re actively working to improve.

If you’re not sure how to frame it, use a structure like this:

4) Discuss your marketing plan

Once you’ve clarified what you sell, the next step is explaining how you plan to get it in front of the right people and keep them coming back.

This section shows stakeholders how your business attracts, converts, and retains customers in the current market. For an existing business, it’s also a way to show how your approach has evolved over time.

We see this missed often. Founders describe their product well, but when it comes to marketing, the plan sounds either outdated or vague. There’s no clear audience, no specific tactics, and no way to track what’s working.

Here’s how we usually structure this section with clients:

• Target audience: Include basic demographics, interests, and any behavior patterns you’ve identified from actual customer data.
• Marketing channels: Where you’ll reach them: Email, content, paid ads, SEO, social, events, etc.
• Promotions & partnerships: Any offers, discounts, loyalty programs, or brand partnerships you’re using to drive growth.
• Positioning strategy: Include messaging, tone, and what makes your product different in the eyes of your customer.
• Performance tracking: What you’re measuring and why. Use real KPIs like CAC, conversion rate, CTR, retention, or ROAS.
• Market insights: Add 1–2 insights from recent research.

Here’s a format you can use to lay it out cleanly:

The best marketing plans don’t try to do everything. They focus on the right people, use a few channels well, and make every dollar count. That’s what you want this section to reflect.

5) Outline your operational plan

Outlining your operational plan will provide insights into how efficiently your business runs. What happens after a sale? How do you keep things consistent? Where does it break under pressure?

A lot of founders we work with haven’t documented this before. They’re running everything from memory or WhatsApp threads. That’s fine early on but if you’re writing a serious business plan, we help turn all that informal knowledge into a clean, structured operations section.

Here’s how we help founders do it:

• Walk through what a typical day or week looks like in your business
• Document the real systems you use, even if it’s just spreadsheets and Slack
• Map out your workflows, from production to fulfillment to post-sale support
• Spot gaps that are slowing you down or keeping you from scaling
• Write it all up in clear language that shows you’re in control

You don’t need to sound fancy. You need to sound like you know how to run your business.

Here’s the kind of table we use to organize it in your plan:

6) Provide information about your management team

For an existing business, your team already plays a direct role in results. This section shows who’s responsible for that performance—and who’s positioned to drive the next stage of growth.

Most founders know this part matters, but they often rush through it or copy-paste old bios without updates. We help clean this up. That includes rewriting roles to reflect what people actually do, connecting background to impact, and making sure everything reads like a leadership team—not just a list of names.

Here’s what we include:

• Name and title of each core team member
• Their current responsibilities (not just job titles)
• Key experience and how it helps the business
• Any gaps being filled by advisors, mentors, or external experts
• Any upcoming leadership transitions or hiring plans

This section is about clarity and trust. You don’t need a perfect org chart. You just need to show that the right people are in the right seats, or that you have a plan to get there.

7) Present your financial projections

This is where you show how your business performs and where it’s going next.

Unlike a startup plan, you have actual numbers to work with. That’s a strength. We help founders use past financials to build credibility, then extend that story into a clear 3–5 year forecast.

Here’s how we build this section with clients:

• Start with recent performance: Revenue, net profit, cash flow trends
• Add historical statements (P&L, balance sheet, cash flow) for context
• Build forward-looking projections based on current trends and strategy
• Include funding needs (if any), and where the money will go
• Keep the tone realistic—optimistic, but grounded in real performance

When we help founders write this part, we also clean up formatting, highlight the right metrics, and explain any context the numbers alone can’t show.

8) Include appendices

This section backs up everything you’ve written.

We help founders decide what’s worth including and clean up the formatting so it’s easy to scan. Here’s what usually makes the cut:

• Charts and graphs: Visuals for financial projections, market analysis, or other vital data.
• Legal agreements: Contracts, partnership agreements, or lease documents.
• Technical specifications: Product blueprints, patents, or proprietary processes.
• Market research: Detailed reports or surveys supporting your marketing strategy.
• Resumes of key personnel: CVs of management and key team members.
• Product samples or mockups: Photos or design mockups of products.
• Other supporting documents: Licenses, permits, certifications, or any other relevant paperwork.

The elements to include in your existing business plan end here. Ensure you avoid unnecessary details that could make your plan overly lengthy. 

If you want to know the ideal length of your business plan check out our blog that outlines the right length of business plan and craft your plan accordingly.

8 mistakes to avoid while writing a business plan for an existing business

Nearly 45% of businesses fail within their first five years, and more than half don’t survive beyond a decade. One of the primary reasons for this is poor business planning.

So whether you’re on your 9th year of business or 99th, ensure you steer clear of these planning mistakes:

1) Overcomplicating the plan

Including unnecessary information can confuse readers, whether you’re writing a plan for an established firm or a startup. It leads them to focus on irrelevant details rather than the core objectives.

Further, over-complicating it with jargon or complex language can divert stakeholders' attention, making it difficult for them to understand your key messages.

2) Neglecting updates

Failing to conduct thorough market research can lead to misguided strategies which can quickly start the downfall of your well-established company.

Therefore, it’s essential to understand the current trends in your industry, your target audience, and the competitive landscape, and include this information in your business plan. Failing to incorporate these updates may hinder your ability to make informed decisions.

3) Ignoring the competition

Failing to thoroughly analyze your competition can lead to missed opportunities and threats, hampering your growth. Neglecting to identify competitors and understand their strengths and weaknesses may result in ineffective strategies and lost market share.

4) Vague goals and objectives

Vague objectives make it difficult to assess progress and success. Ensure your established business’s goals are specific and attainable to provide direction and focus.

5) Underestimating financial projections

Omitting financial projections can undermine your business plan. Stakeholders need to see expected income, expenses, and profitability to assess your business's viability. Without this information, it becomes challenging to secure funding or attract investors.

6) Lack of focus on execution

Not emphasizing the execution of your strategies is a critical error. A business plan shouldn’t only outline goals and strategies but also detail how you intend to implement them. Failing to provide a clear execution plan can lead to confusion and hinder your established business's growth.

7) Skipping the marketing plan

Failing to outline clear marketing strategies is a major mistake. Your business plan should detail how you plan to reach your target audience and promote your products or services. Without a solid marketing approach, attracting customers can be challenging.

8) Not addressing risks

Not addressing potential risks in your business plan can lead to unforeseen challenges.

Stakeholders need to see that you’ve identified risks and developed strategies to mitigate them all these years and intend to address the potential or future risks as well.

Failing to do so can make your business appear unprepared for uncertainties.

Take a look at the table below to explore the distinctions:

Wrapping up

In this blog, we explored how to write a business plan for an existing business, mistakes to avoid while writing a business plan, and the difference between an existing business plan and a fresh one.

With this information, you can write a business plan for your established business with much detail and efficiency. However, writing a business plan for an existing business is complex.

While you can find a dozen options for planning tools online, the expertise of business planning consultants is unmatched any day.

Hire a plan consulting firm like Plangrowlab or get a planning tool like Upmetrics; both are great options. The question is how much time and money you wish to spend.

No matter what you choose, we’re always here to help. Happy business planning 🙂