<prompt> Human: My father in law offered to sell a home he purchased for us, that we currently live in, for half of what he paid with 0 interest and 0 down.We would like to take up his offer, but are there any tax or other benefits Im missing out on by not getting charged interest that would presumably outweigh the interest?Ideally we would have an actual contract to sell written up by a lawyer. Im not entirely sure how to go about that without involving a bank. But then my wife would like for this to help her build credit, as she has none. But for that, wed have to go through a bank, right? Or is there some other entity we can use that will report to the credit agencies?  <response>: Talk to a lawyer and CPA about this - your father can cut you a very generous deal but there are limits to how generous your FIL can be without incurring tax penalties. The taxes may not be a big deal anyways but you will definitely want to do things by the book and you will definitely want a formal sales contract drawn up by an attorney. 