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 parties are required to file Form 8594 alongside their respective tax returns to report the tax consequences of the asset acquisition accurately. The buyer must also file Form 8594 for the transaction.