An automated resource management system for a retail business includes a point-of-sale system and an access control system in communication with the point-of-sale system. The access control system can be configured to detect, and/or receive a signal from, an electronic device associated with a customer of the retail store, such as a cellular phone. Upon automatic detection of a billable event (e.g., retrieving an item from a vending machine) while the access control system determines that the user is within the retail store, automatic billing or invoicing of the customer by the point-of-sale system can occur.