Scenario A: An unmarried taxpayer pays 70% of household costs and lives all year with their 10-year-old child.
The child otherwise meets the qualifying-child tests. HOH may be available; verify all facts and documentation.
Scenario B: A taxpayer supports a parent living in a separate apartment. The parent may be a qualifying relative,
and special HOH rules may apply if the taxpayer pays more than half the cost of keeping up the parent’s main
home. Verify the parent’s income, support, and other tests.
Scenario C: Two unmarried parents share a home with a child. Only one pays more than half the household
costs. The dependent and HOH outcomes may differ; apply all tests and tie-breaker rules rather than relying on an
informal agreement.