My girlfriend and I currently live in separate households. We are thinking of moving in together and as a result, renting her house. She has a two children (17 & 4) from a previous relationship and I have one (7) from mine. She is employed and makes 50k. I make almost twice her salary.

We obviously will be filing separately since we are not married. I figure I still file Head of household, but what does she file under? Does she claim her kids or do I? Do I claim her? What is the effect of the rental income on her house?

Unrelated to taxes, Her 17yo is also applying for college. Do you know if this will effect FASFA since he is not my child?

Thanks in advance if you can answer any of this.

We obviously will be filing separately since we are not married. I figure I still file Head of household, but what does she file under? =======>As you do, she may file her return as a HOH aslongas she qualifies the requirements to file as a HOH. As long as she is the one who paid for more than half the cost of keeping up the home where she all is living and her kids are claimed as her dependent, she can file as head of household.

Does she claim her kids or do I? ====>either you or she does do that; Usually you can?t claim a child as a dependent if the child can qualify as a dependent for someone else (your girlfriend or their parent or etc.) However there is a special exception. If your girlfriend is not required to file a tax return due to low income and she does not file or files solely to get a refund of withheld income, then you can claim her kids as your dependents on your tax return. If she files only to get an earned income credit, you can?t take her kids as your dependent.however, aslongas you may claim her as your dependent, then you may claim her kids as your dependents on your return. Note: If your girlfriend and/or her son are the only dependents listed on your tax return, you cannot file as head of household. i mean you also need to claim your own kid on your return also to claim your rreturn as HOH.
Do I claim her?=======>>asmentioned above; you may claim her on your 1040aslongas your girlfriend has lived with you for all of 2017, her gross income is less than $4.05K and you?ve provided more than half of her total support, you could claim her as a dependent on your tax return.

What is the effect of the rental income on her house? =====>>as said, aslongas her income for 23017 is over $4,050, her persianl exemption amt for 2017, due to her rental income reported on her 1040, then you can not claim her as your dependent on your 2017 return since her gross income exceeds $4,050.