Step daughter and girlfriend

[Jreed90]

My girlfriend has a daughter before me and we have two kids together. She's a stay at home mom so she doesn't have a w2. I support the house. How would I go about claiming her and her daughter. 

[Bsch4477]

File as Head of Household claiming your biological children as qualifying children and claim your girlfriend and her child as qualifying relatives if they have lived with you all year, they have no income and you provided more than half of their support. 

[Mike9241]

that daughter is not your stepchild (qualifying child) because you are not married to her mother. she could be a qualifying relative since you seem to be saying your girlfriend is not required to file a tax return. 

you have not provided enough info to provide further guidance.

you can use this IRS website to see if either qualify to be claimed as a dependent 

https://www.irs.gov/help/ita/whom-may-i-claim-as-a-dependent 

[xmasbaby0]

We do not have enough information -- did your GF's child live with you--- or did the child live with another parent?     If you and your GF and her daughter (who is not your bio-child) lived with you for the entire year in 2024 and you provided over half of their support, they may be "qualified relative" dependents for whom you will get the $500 credit for other dependents.  That is a non-refundable credit that can reduce your tax owed.   You will not get child-related refundable credit like child tax credit or earned income credit for your GF's child, since you and her mother are not legally married.    Since you have two children that are your own bi0 children, you can file as Head of Household and claim your two children as qualifying child dependents for HOH filing status and for any child-related credits for which you are eligible.

WHO CAN I CLAIM AS A DEPENDENT?

You can claim a child, relative, friend, or fiancé (etc.) as a dependent on your 2024 taxes as long as they meet the following requirements:

Qualifying child

• They're related to you.
• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They're under the age of 19 (or 24 for full-time students).
• No age limit for permanently and totally disabled children.
• They lived with you for more than half the year (exceptions apply).
• They didn't provide more than half of their own support for the year.

Qualifying relative

• They don't have to be related to you (despite the name).
• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They lived with you the entire year (exceptions apply).
• They made less than $5050 in 2024 (not counting Social Security)
• You provided more than half of their financial support.

[Opus 17]

By the way, Turbotax has a dependent interview that will do all this for you if you read and answer the questions carefully for each possible dependent.

Your children together can be your dependent, no problem.  This is a type called "qualifying child" dependent.

Your girlfriend can be your dependent if:

1. she lived with you all 365 days of the year 

2. her gross taxable income is less than $5400

3. she does not file a tax return, or only files a tax return to claim a refund of withholding and claims no other dependents, credits or deductions.

4. You pay more than half her total support.

This is a type of dependent called "qualifying relative."

Your girlfriend's child can be your qualifying relative dependent if:

1. she lived with you all 365 days of the year 

2. her gross taxable income is less than $5400

3. she does not file a tax return, or only files a tax return to claim a refund of withholding and claims no other dependents, credits or deductions.

4. You pay more than half her total support.

5. No other blood relative qualifies to claim her as a dependent ahead of you.  

Test 5 is usually simple but can get tricky.  If the child lives in your home all year, the only blood relative who could claim her would be a relative who also lived in the home with your family. For example, if you share the home with your girlfriend's mother, grandmother, brother or sister, they may be able to claim the child ahead of you.