Get an electronic lock. 

Hi all new, here but not to bigger pockets.I own a 4 unit and looking to own something bigger next.All my tennets pay on time but have asked if they could do it on thier phone and send it.This is the way of the future...

Buying a single family home means you're covering all these costs as well.Don't forget about the additional upfront costs especially since they're new builds, furnishings, decor, electronics, cable/internet, small appliances, kitchen wares, window treatments, etc.    

I use ABT Electronics in Glenview, IL.

This will serve you your entire career.The package should be electronic so you can email it as a follow up as well as drop a hard copy when you meet with the banks.

@John Collins  Somewhere they should be a metal box on the wall that houses all the electronics.

Sounds like you have electronic regulator. 

What is the best esign software out there?

Most people take this money and essentially throw it away on unnecessary stuff -- electronics, restaurants, vacations, cars, etc.

Between electronic and the bank set up perhaps I can limit my gas/time effectively while collecting rent.