No minimum number of units. In fact, 80% of our units are single family residence.
We have Spanish speakers on staff, but all of our automated texts/emails are in English. So that come some times be an issue for Spanish only speakers. Generally we have to get on the phone with them.
We charge $25 + $1/unit per month for handling all tenant calls, troubleshooting, and emergency coordination. For $25 + $10/unit we do coordination for every time of job (snow shoveling, cleaning etc.) The monthly subscription does NOT include the cost of the handyman/contractor going out to do work.
No plans to go into full on property management. We feel like maintenance is a big enough headache to solve for now!