Q: When may a married person file taxes as Head of Household?
A: When they are “considered unmarried”:
The IRS says that:
“You are considered unmarried on the last day of the tax year if you meet all the following tests.
You file a separate return (defined earlier under Joint Return After Separate Returns ).
You paid more than half the cost of keeping up your home for the tax year.
Your spouse did not live in your home during the last 6 months of the tax year. Your spouse is considered to live in your home even if he or she is temporarily absent due to special circumstances. See Temporary absences , under Qualifying Person, later.
Your home was the main home of your child, stepchild, or foster child for more than half the year. (See Home of qualifying person , under Qualifying Person, later, for rules applying to a child’s birth, death, or temporary absence during the year.)
You must be able to claim an exemption for the child. However, you meet this test if you cannot claim the exemption only because the noncustodial parent can claim the child using the rules described in Children of divorced or separated parents (or parents who live apart) under Qualifying Child in chapter 3, or in Support Test for Children of Divorced or Separated Parents (or Parents Who Live Apart) under Qualifying Relative in chapter 3. The general rules for claiming an exemption for a dependent are explained under Exemptions for Dependents in chapter 3.”
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Basically, if you and your spouse separated before July 1; you provide most of your own support and your child (whom you also support) lives with you, you may be able to file head of household, even though you are married! This has important implications not only for your filing status, but for the earned income credit as well.