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. Did you buy or sell a business during the tax year? If so, you may need to file IRS Form 8594 with your federal tax return. Action wil be allocated.