In a complex/estate, utilities are usually billed on a bulk basis by Eskom/Municipal supplier.
Each individual unit is billed in arrears for its individual consumption. Each owner is responsible for making payment of their portion of electricity used.
Increasingly, complexes / estates are faced with the very real problem of late payments by owners, causing significant cash flow problems for the building, resulting in funds allocated for security, maintenance etc. being used for electricity payments which have not been recovered from non-paying owners.