What are the conditions to file tax return together with friend(not married)?

Question

What are the conditions to file tax return together with friend(not married)?

Answer 1

You cannot be common law married to a friend.

If you have accidentally filed married when you are not, amend the tax return IMMEDIATELY.  For g*y marriages in Mass., they must also file as single as the IRS follows DOMA and doesn't recognize that marriage for federal tax purposes.  The same goes for registered partnerships in the other 5-6 states that have them.

Answer 2

To file together, you have to be legally married.  So there aren't any conditions that would allow filing together otherwise.

Answer 3

In states that recognize Common Law marriages, you can also file joint returns. This is true even if you later move to a state that does not recognize Common Law marriages.