You must submit a paper filing and a supplemental form to the Assessor's Office. Both forms are on our e-filing site.There are three ways to file the Business Property Statements (571-L) 1. Filing your statement via the internet 2. The purchase and sale agreement for the business entity or assets is a vital document. Register Your Business. Both the seller and purchaser of a group of assets that makes up a trade or business must use Form 8594 to report such a sale.