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. Form 8594 is a tax document required in certain business sales where the buyer acquires assets rather than stock or equity. Enter your name and taxpayer identification number (TIN) at the top of the form. Then check the box for Purchaser or Seller. CAUTION. The federal amounts that you use on your Arizona return may not be the same as the federal amounts from your federal tax return. Individuals can find all tax forms and instructions on the ADOR website or visit our local offices. For a list of forms and schedules available in ATX, please click on federal forms or select a state.