Is a business plan required to purchase an existing business?

Yes, a business plan is required to buy an existing business - especially if you will be seeking financing. The current owners may already have a business plan, but this is not your plan. Your plan needs to take into consideration the transition that will occur as the business changes hands. For instance, if you are purchasing a retail business that has a steady flow of customers, how will the transfer take place without disrupting normal business activities? The plan also needs to detail any changes that you intend to make to the business model, pricing and marketing. It should also include an updated personnel plan and financials.