In property situations where submetering is mechanically or structurally unfeasible, or cost prohibitive, RUBS (Ratio Utility Billing Systems) offers a fair and legal alternative method of determining individual tenant responsibility for utility consumption. The RUBS method calculates usage based on a pre-determined formula that can include square footage and occupancy numbers as well as other factors in order to allocate appropriate billing charges for each unit, thus preventing arbitrary or theoretical division of tenant usage cost, and relieving building owners of shouldering the full cost of utilities as determined by the master meter. JIT provides analysis and calculation of the appropriate RUBS formula based on industry standards and state or municipal regulations for RUBS billing where the property is located, generates and delivers invoices, and can collect payments for those interested in full service.