If they otherwise meet all of the requirements to claim the earned income tax credit (EITC), unmarried parents with a qualifying child may choose which parent will claim the credit.

If there are two qualifying children, each parent may claim the credit based on one child.
One parent may claim the credit based on both children.
If both parents claim the same qualifying child for the EITC, but don’t file a joint return together, the IRS will apply tie-breaker rules and treat the child as the qualifying child of the parent with whom the child lives for the longer amount of time in the tax year. If the child lives with each parent for the same amount of time, the IRS will treat the child as the qualifying child of the parent who has the higher adjusted gross income (AGI) for the tax year.
If no parent can claim the child as a qualifying child, the child is treated as the qualifying child of the person who has the highest AGI for the tax year.
If a parent can claim the child as a qualifying child but neither parent claims the child, the child is treated as the qualifying child of the person who has the highest AGI, but only if that person’s AGI is higher than the AGI of any of the child’s parents who can claim the child as a qualifying child.