35 Miss. Code. R. 6-03-06-102.04
If the applicant owns less than the one hundred sixty (160) acres in the county in which the dwelling is located, he is permitted to add to his homestead exemption claim any eligible property located in an adjoining county. Again the limits of one hundred sixty (160) total acres and five (5) miles from the home tract are placed on the property claimed for homestead exemption. In the case of land in an adjoining county, the applicant must file in both counties. First the applicant should file in the resident county and have two certified copies made of the application and carry them to the adjoining county. These copies should contain the assessed value given the land and dwelling and the total assessed value given the land allowed by the resident county. One copy is sent with the original application of the adjoining county that is sent to the Tax Commission (do not attach) and the other copy attached to the duplicate that is kept on file in the adjoining county.
35 Miss. Code. R. 6-03-06-102.04