@kmayosr1
What you were told is all basically correct, but not exactly. But the bottom line is YOU cannot claim them (another taxpayer with slightly different circumstance might). It's complicated.
"I was told I could not clam my fiancé kids because i am not the father, even though I provided for the the whole year."
You cannot claim them as "Qualifying Children" (and get the child tax credit and EIC) because you are not closely related. If you supported them AND lived with them ALL year, you could claim them as "Qualifying Relative" dependents and get the (up to) $500 Other dependent credit.
"I was also told if we were married , I could claim them".
Correct. A step child is the same as a biological child for tax purposes.
"Her and the children's father were never married"
That's not relevant for taxes.
"They stayed with me since June".
That means they did NOT live with you all year. You cannot claim them at all.
There are two types of dependents, "Qualifying Children"(QC) and standard ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit and student status test, a relationship test and a residence test. Only a QC qualifies a taxpayer for the Earned Income Credit and the Child Tax Credit. The Other dependent (qualifying relative) credit is worth (up to) $500 per dependent and is non-refundable. That is, it can only be used to reduce an actual tax liability.
A person can still be a Qualifying relative dependent, if not a Qualifying Child, if he meets the 6 tests for claiming a dependent:
- Closely Related OR live with the taxpayer ALL year
- His/her gross taxable income for the year must be less than $4300 (2020).
- The taxpayer must have provided more than 1/2 his support
In either case:
- He must be a US citizen or resident of the US, Canada or Mexico
- He must not file a joint return with his spouse or be claiming a dependent of his own
- He must not be the qualifying child of another taxpayer
In addition to the above requirements, to claim your girlfriend's children, they must meet all of the above requirements and:
--- your girlfriend must not be required to file a return,
--- she does not file a return claiming the children
