Fill out the Homestead Tax Credit, 54-028 form. Return the form to your city or county assessor.Eligible claimants who are 65 years of age or older on or before January 1 of the assessment year are now eligible for a homestead tax exemption. Address: City: State: ZIP: Phone: Answer these questions to determine eligibility: 1. Are you currently an Iowa resident? Iowa law provides for a number of credits and exemptions. You can apply for this in person at the Assessor's Office or online. The Residence Homestead Exemption Application form is available from the details page of your account. But if you wanna know how to work it out yourself, put stamp duty calculator.