File this form and all supporting documentation with the appraisal district office in each county in which the property is located generally between Jan. Tarrant County Commissioners increased the homestead property tax exemption from 10 percent to 20 percent.The typical deadline for filing a county appraisal district homestead exemption application is between January 1 and April 30. Attention Tarrant County Homeowners! Beware of solicitors charging fees to file your homestead exemption forms. First, fill out the application specific to your County Appraisal District, then mail all of the documents to the Appraisal District for your County.