"[S]erious property owner" -- This phrase sounds like a "no true Scotsman" test. What exactly qualifies as "serious"? I know numerous people who own a bunch of properties and don't have a separate company structure, as there is no tax advantage (in my jurisdiction). They use local real estate agents to find new renters when old renters leave. It's pretty simple. And, the agent also coordinates monthly payments (to the owner) and any repairs.