You (or the purchaser or transferee) must complete Form CBS-1, Notice of Sale, Purchase, or Transfer of Business Assets. Each sale has different pros and cons.The seller should be ready to provide detailed information about the business's assets, liabilities, revenues, costs, and customer base, among other things. To sell a business in Illinois, you'll need various legal documents, including a bill of sale, asset purchase agreement, and non-disclosure agreements. Form 4797 is used for reporting the sale of various types of business property, such as real estate, equipment, and assets used in a trade or business. If you need additional information, you may call our Chicago office weekdays between a.m. Both the buyer and seller must complete IRS Form 8594 during the sale to report the sale and purchase of business assets.