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. Pursuant to Section 1060, both the buyer and the seller must file Form 8594 (Asset. The tax professional who comes into contact with such a situation should consider the need to file Form 8594, or to revise the valuation of specific assets. Form 8594 breaks the types of assets of the business into seven categories.