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. As a rule, the starting point for your Arizona return is your federal adjusted gross income. Who Must File Form 8594? Both the seller and purchaser of a group of assets that make up a trade or business need to file Form 8594. – Both the purchaser and seller are required to file Form 8594. – The Form 8594 must be attached to each filer's timely filed Federal income tax return. Go to Screen 65, Asset Acquisition Statement (8594) (Screen 58 for S-Corp).