If you want to claim the Earned Income Tax Credit, you cannot be a qualifying child of any other taxpayer. You’re considered a qualifying child if you’re:

• a son, daughter, stepchild, foster child, or descendant of those
• a brother, sister, half-sibling, step-sibling, or a descendant of those

AND

• You’re under the age of 19 at the conclusion of the tax year, and are younger than the taxpayer to whom you may be a qualifying child.
• Are a full-time student under the age of 24, and younger than the taxpayer claiming you.
• Have lived with the taxpayer for over half of the year in their house
• Are not filing a joint return with your spouse

If none of the above apply to you, you are not a qualifying child of anyone else, and therefore are free to claim the EITC if you meet all of the other requirements.

If you are a qualifying child of another taxpayer, you are ineligible to claim the EITC, regardless of whether the original taxpayer claims it or not.

If you file a joint return with your spouse for the purpose only of obtaining a refund of income tax, then you may still be a qualifying child, so be sure to check the rest of the requirements before assuming a joint return makes you eligible to claim the EITC.