You can accept rent from anyone.... however, if you do you may just accidentally create a tenant who then has lots of tenant rights and you might have just waived your right to screen them, approve them etc. Just once?, not an issue most likely. Do it a few times and they, their family, their cousins, their dogs, and all their junk cars have just become your tenants. It is similar to accepting rent (3 months or so) from a tenant with a known violation (illegal pets, unauthorized roommates etc) you create "waiver" and loose your right to evict for those actions. Suggest you purchase the Landlord Law Book from the Oregon landlord group ORHA and join your local landlord association. It's never cut and dried. That book is very helpful and your local group is a great resource. In my neck of the woods it is the Rental Owners Association of Douglas County chapter of the ORHA.