What is Head of Household?
Head of household is a favorable filing status for unmarried people who support a qualifying dependent and keep up a home for them.
How it works
To qualify, you must be unmarried (or considered unmarried) at year-end, pay more than half the cost of running your household, and have a qualifying person live with you more than half the year. In return you get wider brackets and a bigger standard deduction than single filers.
A quick example
What people get wrong
"More than half the cost of the home" is a real test — rent, utilities, groceries, and repairs count. Keep a rough tally if your situation is borderline, because it's a common audit flag.