You are required to report all sales of businesses to the Illinois Department of Revenue. Disclosure of this information is REQUIRED.Utilize a purchase and sale agreement when conducting transactions that involve the buying and selling of goods or real estate. Address. City. State. Zip. County. Permanent Index Number(s) of Real Estate: ______-______-______-______. The Real Estate is vacant and unimproved. Find out if you qualify to exclude from your income all or part of any gain from the sale of your personal residence. Taxpayers who are selling their home may qualify to exclude all or part of any gain from the sale from their income when filing their tax return. When selling residential property, one must carefully consider the tax implications. Finalizing the Sale: Completing the transaction with the transfer of property and funds. Steps to Sell Commercial Property in Illinois.