Charging Tenants Variable Utilities Each Month

[Jake Earl]

Hi! I am self managing all of my properties and at the beginning I just signed leases with fixed utility amounts for simplicity. I’m realizing that was a mistake because the tenants are running up the utility bill. Putting the utilities in my tenants name isn’t an option for some of the units I own because they’re multi unit properties that aren’t separately metered.
My question is this: is there an online portal available that allows you to easily go in and charge a variable expense like utilities every month? I’m finding sites like Rentler or Azibo only allow landlords to set a fixed amount each month for rent and I really don’t want to be charging my tenants rent and utilities on a different platform. Any ideas are greatly appreciated - thank you!