Form 8594 is a tax document required in certain business sales where the buyer acquires assets rather than stock or equity. 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. 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. Both the buyer and seller must complete IRS Form 8594 during the sale to report the sale and purchase of business assets.