<prompt> Human: My boyfriend is moving into my house. What is a fair way to split costs?My mortgage costs around 400 per month. as its not his mortgage is it really fair to ask him to pay half? Should I ask for half the bills and no contribution to the mortgage? TL;DR: how to split living costs fairly regarding mortgage Assistant: I would charge him 12 of each. I assume its still less than renting on his own?Human: He lives at home so currently doesnt pay rent. Do you think its fair to ask for half the mortgage when its essentially going into my pocket at the end of it?  <response>: The thing about owning a home and having a significant other move in is that you are no longer just their significant other. Youre also their landlord. This is just how it works. If you both lived at home or in your own separate apartments and you moved out together into a rental apartment how would you split the rent bill? Obviously youre in a position to grant concession toward your boyfriend seeing as you are the landlord rather than both of you being at a strangers mercy, but he should still be paying rent. I think half of market rate for a comparable room would make sense, depending on what that is. 