Share your insights or perspective on the financial matter presented in the input.

In-laws moving in (financial/tax implications)?
You are "pool[ing] the sales from both houses as downpayment on the new house." But they are going to pay you rent.  Your question as it stands, just opens more questions. What, exactly is the ownership of the new house? If your's (and your wife's) was the money a gift?  Ignoring the gift, if that's what it is, and if the in-law suite is 25% of the house value, you have a rental. You claim 25% of the expenses, including property tax and mortgage interest, along with 25% of the utilities, unless their part has its own meters.  That's a start, if you add details, I may edit my answer. (Not to be pedantic, but whose parents are they. They can't be "our in-laws," can they?)