The term 'Billing Partner' can be summarized as a job description for a Costar, which is a six-letter word. A Costar is a person who is responsible for billing and managing customer accounts. They are also responsible for ensuring that all customer payments are received on time and accurately. They must have excellent organizational skills and be able to work with customers in a professional manner. Additionally, they must be able to handle customer inquiries and complaints in a timely and efficient manner.