Lastly, to qualify as a head of household, you need to have a dependent, either a qualifying child or another qualifying relative. For IRS purposes, a qualifying child is your biological child, a stepchild, an adopted or foster child, or any younger relative, including brothers and sisters, half-brothers and stepsisters, even nieces and nephews [source: Internal Revenue Service]. The child must be 18 or younger (23 or younger if a full-time student) and you must claim the child exemption on your taxes. The child must also live in your home for at least 6 months of the tax year [source: Internal Revenue Service].
Dependents can also be relatives other than children. If you pay more than 50 percent of a relative's total support for the year, and that person lives with you for at least half of the year, then that person is your dependent for IRS purposes. To calculate total support, include the following expenses:
Please note, however, that if a relative earns more than $3,700 in gross annual income, even from Social Security benefits, he or she no longer qualifies as your dependent [source: Internal Revenue Service].
Confused yet? Welcome to the tax code.
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