Generally, the deadline to file an application for an exemption is April 30. How to Complete the Application.Fill out the other side of this application completely. You must apply with your county appraisal district to get a homestead exemption. Applying is free and only needs to be filed once. Filing for your homestead exemption is January 1 and no later than April 30. The application may be available online or in person. First, you will need to fill out Form 50114, the Residence Homestead Exemption Application. To fill out the Homestead Exemption form, gather your necessary documents, including proof of age and residency. Take advantage of tax breaks as a senior.