But usually your don't want piss off IRS if they are auditing your tax return. In addition, if the check is made to them and the apartment is under their name, how can you argue it is not a gift? Of course, if you make purchase for yourself, that is another story. But if you let them stay at your place without paying rent, under the code you may still have to pay tax if the FMV of the rent exceedds $12,000 annually. Again, you may want check with your accountant or tax lawyer first.