Alabama nonresidents individuals must file if:
Filing status is: And gross income from Alabama source exceeds:
Single, MFS - $1,500 × Alabama percentage of adjusted total income.
Head of Family, MFJ - $3,000 × Alabama percentage of adjusted total income.
Gross income includes all income except income specifically exempted by Alabama state law.
Alabama income does not include gifts, money, or other property that was inherited.
For additional information follow the link https://revenue.alabama.gov/individual-corporate/faq/individual-income-tax/
