Tenn. Code Ann. § 7-64-203

Any taxpayer who owns residential property as such taxpayer's principal place of residence, whose combined annual income from all sources is less than twelve thousand dollars ($12,000), or in the event of a married couple or in the event more than one (1) person is living permanently in the principal residence, this limitation of twelve thousand dollars ($12,000) on income from all sources shall apply to the combined income of both the husband and wife and/or all family members residing in the residence.