The duties and responsibilities of a Billing Specialist include sending invoices and account updates to clients, receiving, sorting, and tracking incoming payments, addressing and resolving client questions and issues relating to invoices, and providing regular, accurate reports of billing data.A Billing Specialist oversees the tasks of sending new invoices to clients and ensuring all outstanding invoices are paid in full and on time. They are client-focused and assist them with any issues with invoices.A billing system operator typically uses computers that run billing applications that are customized to the organization's needs. The automated software enables information to be compiled quicker and with greater accuracy. Some on-the-job training may be required to use the program.