No. You cannot use your BF's children as qualifying dependents to file as HOH because they are not related to YOU, and neither is your BF. You must have a qualifying dependent who is related to you in order to file as HOH. Or....do you have another child--who is related to you and who would be your qualifying dependent?
As for claiming them as dependents......they have to live with you the WHOLE year--not just "most" of the time in order for you to claim them as your dependents for the $500 credit for other dependents---which is the best you could get for claiming them. You are not eligible to get child tax credit, earned income credit or childcare credit for your BF's children.
IRS interview to help determine who can be claimed:
https://www.irs.gov/help/ita/who-can-i-claim-as-a-dependent
https://ttlc.intuit.com/questions/3113432-who-can-i-claim-as-my-dependent
Am I Head of Household?
https://ttlc.intuit.com/questions/1894553-do-i-qualify-for-head-of-household
https://ttlc.intuit.com/questions/2900097-what-is-a-qualifying-person-for-head-of-household
If you qualify as Head of Household, when you enter your marital status (single or married filing separately) into MyInfo, and then enter your qualifying dependent, TurboTax will offer HOH as your filing status.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
