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.Enter your name and taxpayer identification number (TIN) at the top of the form. Then check the box for Purchaser or Seller. Filing your income tax return doesn't need to be complex or difficult. We've put together information to help you understand your state tax requirements. Line-by-line instructions for filing your Utah income tax return. Did the organization engage in any activity not previously reported to the IRS? If "Yes," attach a detailed description of each activity. OMB No. 1545-1021. Attachment.