If a child *can* be be a qualifying child dependent of more than one taxpayer then the tie breaking rules come into effect. A parent always comes before a non-parent.
But first you must meet
the rules for a qualifying child.
---Tests To Be a Qualifying Child---
(Must pass ALL of these tests)
NOTE: If a child passes all of these tests he must say “yes” on his/her own tax return (if he/she files one) that another taxpayer CAN claim him/her as a dependent even if they DO NOT claim him/her)
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 2020, (b) under age 24 at the end of 2020 and a full-time student* for any part of 5 months of 2020, or (c) any age if permanently and totally disabled and must be younger than you (or your spouse if filing jointly).
3. The child must have lived with you for more than half of the year (There are exceptions for temporary absences such as school, illness, business, vacation, military service).
4. The child must not have provided more than half of his or her own support for the year.
See Worksheet 3-1. Worksheet for Determining Support
https://www.irs.gov/publications/p17#en_US_2020_publink1000171012
5. If the child meets the rules to be a qualifying child of more than one person, you must be the person entitled to claim the child as a qualifying child.
6. The child is not filing a joint return.
7. The child must be a U.S. citizen, U.S. resident alien, U.S. national, or a resident of Canada or Mexico
*A full-time student is a student who is enrolled for the number of hours or courses the school considers to be full-time attendance during some part of each of any 5 calendar months of the year.
See IRS Publication 17 for more information.
https://www.irs.gov/publications/p17
=====
Then the tie breaking rules take effect.
Qualifying Child of More Than One Person
[Quote from IRS Publication 501]
Sometimes, a child meets the relationship, age, residency, support, and joint return tests to be a qualifying child of more than one person. Although the child is a qualifying child of each of these persons, only one person can actually treat the child as a qualifying child to take all of the following tax benefits (provided the person is eligible for each benefit).
1. The child tax credit or credit for other dependents.
2. Head of household filing status.
3. The credit for child and dependent care expenses.
4. The exclusion from income for dependent care benefits.
5. The earned income credit.
The other person can’t take any of these benefits based on this qualifying child. In other words, you and the other person can’t agree to divide these tax benefits between you.
Tiebreaker rules.
To determine which person can treat the child as a qualifying child to claim these five tax benefits, the following tiebreaker rules apply.
1 - If only one of the persons is the child's parent, the child is treated as the qualifying child of the parent.
2 - If the parents file a joint return together and can claim the child as a qualifying child, the child is treated as the qualifying child of the parents.
3 - If the parents don't file a joint return together but both parents claim the child as a qualifying child, the IRS will treat the child as the qualifying child of the parent with whom the child lived for the longer period of time during the year. If the child lived with each parent for the same amount of time, the IRS will treat the child as the qualifying child of the parent who had the higher adjusted gross income (AGI) for the year.
4- If no parent can claim the child as a qualifying child, the child is treated as the qualifying child of the person who had the highest AGI for the year.
5 - If a parent can claim the child as a qualifying child but no parent does so claim the child, the child is treated as the qualifying child of the person who had the highest AGI for the year, but only if that person's AGI is higher than the highest AGI of any of the child's parents who can claim the child.
Subject to these tiebreaker rules, you and the other person may be able to choose which of you claims the child as a qualifying child.
[end quote]
https://www.irs.gov/publications/p501#en_US_2020_publink1000220917
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
