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. Form 8594 must also be filed if the purchaser or seller is amending an original or a previously filed supplemental Form.8594 because of an increase or decrease. Form 8594 is a tax document required in certain business sales where the buyer acquires assets rather than stock or equity. Both buyer and seller fill out Form 8594 on their respective tax returns showing the allocation. Taxable Stock Sales. The form you mentioned, Form 8594, is used to report when business assets change hands, and the date you choose can affect your taxes.