The deadline to file a homestead exemption is April 30th; however, you can file a homestead exemption for up to 1 year after the delinquency date of the taxes. The normal delinquency date for taxes in Texas is February 1st. Filing a homestead exemption after the April 30th deadline may result in a refund to the homeowner.
You qualify for a homestead exemption for 2017. You are timely in filing your homestead exemption if you file it by April 30th of 2017, but you have until January 31st 2019 (1 year after the 2017 tax payment delinquency date of February 1st 2018) to file a homestead exemption for 2017. If you have already paid your 2017 taxes by the time you file the exemption, you will be issued a refund by the taxing entities.