You need to communicate ..  

The only way to do that is through a process that you follow every single time and document every single applicant, timestamp them and the communication. 

@Seth Baumgartner, I live in Cincinnati, still own (now) one rental, but had more, have done about a dozen or so flips in the area over the years, here is my take.I am fairly risk adverse, so I don't venture into neighborhoods I don't know inside and out.  

Hot water is usually separated it is just the cold water that is often not.For a very large building a flat fee is the move because the back billing and tracking of who paid for what would be hectic, but for a small MF like a duplex it is very easy.I split the bill by the fractional amount of people who live in the unit.In other words, the amount of people that live in the unit divided by the total amount of people living in the builidng.So if there are 3 people upstairs and 2 people downstairs.the upstairs pays 3/5 of the bill, and downstairs pays 2/5.No need to separate anything, you know the tenants will cover 100% of the bill and this approach is fair. 

It was a fairly nice house, somewhat dated but in good condition. 

Quote from @Johny Omaga: As a private lender, establishing clear communication and transparency with borrowers has been crucial in overcoming any funding challenges.

Because we did a fair amount of work on these units at purchase, we know where the problems are likely to be so we can do a fair amount of phone trouble shooting.

It must be communicated to both buyers and sellers that commissions are not pre-determined by law and are fully negotiable.

@Miriam B.yes Jack is currently a member of my land investing group so I communicates with him there and he answers questions about his training products and raw land investing in general when he has time.

While that is a quick way to communicate, it doesn't have the same impact and may not have the same legal consequences.One thing to think about is what is your goal?