Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

In-laws moving in (financial/tax implications)?
GET A LAWYER. Doing business with relatives is business first, and some effort spent in setting things up and nailing down exactly what the financial relationships and obligations are beforehand can save a lot of agony and animosity later. Assuming it's a legal rental, you may be able to deduct business costs spent on maintaining the rental unit, but of course you will have to declare the rent as income. If it's just a bedroom suite, rather than a full legal apartment, I don't think you can claim it as rental. (Note that whether you decide to share cooking and such is a separate question; apartment in most areas requires its own kitchen and bathroom.) As Joe pointed out, the actual purchase also sounds like it's going to involve a large gift, which has its own tax implications. Either that, or they retain ownership of their share and you get to deal with that if you or they decide to sell.  Again: GET A LAWYER. And a tax accountant or tax lawyer to advise you on those implications. This is not someplace where the average wisdom of the Internet should be relied upon except for generalities; local laws and contract details matter.