This exemption lasts up to four years. Application Due Date: No application is required.Exemption applications must be filed with your local assessor's office. See our Municipal Profiles for your local assessor's mailing address. Douglas County has additional exemptions. You can get an application here General Homestead Exemption Form or you can call 630-208-3818 and one will be mailed to you. Overview. The property tax exemption program benefits you in two ways. First, it reduces the amount of property taxes you are responsible for paying. The BOR accepts exemption applications for approximately 30 days, four times each year. The General Homestead Exemption is granted automatically in most cases.