Can I claim my ex girlfriend's son if I was his sole provider and he stayed in my home for the entire year? We are no longer together.

[privatejett]

The son's father was laid off but worked under the table and paid no child support for the entire year. The son's mother has not worked in years. The son has a regular visitation schedule every other weekend with his dad.

[MinhT1]

You can claim your ex-girlfriend's son as a dependent if he satisfies ALL the following conditions:

1. The person can't be your qualifying child or the qualifying child of any other taxpayer. 
2. The person must live with you all year as a member of your household (and your relationship must not violate local laws). 
3. The person's gross income for the year 2020 must be less than $4,300. 
4. You must provide more than half of the person's total support for the year.
5. The person is a U.S. citizen, U.S. resident alien, U.S. national.
6. The person is not a married person who files a joint return unless that joint return is filed only to claim a refund of withheld income tax or estimated tax paid.

[privatejett]

Thank you for your help. Just for clarification, the son lived with me all year, save for the scheduled alternating weekends at his father's home. Does that still qualify for all year? Also, is his mother's permission required for me to claim him? Thanks again. 

[JohnB5677]

The answer to both questions is yes, but let's talk about getting the mother's permission first.

Even though the child may qualify as your dependent.   The mother (or the father) may claim them on the their tax return.  If that happens the IRS will contact you and the other party to determine the actual status of the child.  That may not be an issue you wish to deal with.  It is best to first contact the parents to confirm that they are not claiming the boy. 

Yes, if the child lived with you for the entire year except alternating weekends, that is considered the full year.

[privatejett]

Can the parents face a penalty for alleging they supported someone they  in fact did not support?

[DMarkM1]

The parents of the child are not required to provide more than half of the child's support in order to claim the child as long as the child does not provide more than half their own support.

If the child lived with a parent for more than 1/2 the year they can claim the child.  The criteria for you to claim a qualifying relative states "The person cannot be the qualifying child of anyone else."  That's why you need to get the "OK" from the parent(s) to claim because they almost always can claim just because they are the parents.  

Here are criteria for claiming a qualifying child.   

1. The child must be your son, daughter, stepchild, foster child, brother, sister, half brother, half sister, stepbrother, stepsister, or a descendant of any of them.

2. The child must be (a) under age 19 at the end of the year and younger than you (or your spouse if filing jointly), (b) under age 24 at the end of the year, a student, and younger than you (or your spouse if filing jointly), or (c) any age if permanently and totally disabled.

3. The child must have lived with you for more than half of the year.

4. The child must not have provided more than half of his or her own support for the year.

5. The child must not be filing a joint return for the year (unless that joint return is filed only to claim a refund of withheld income tax or estimated tax paid).