This chapter analyses and evaluates the current situation during business dealing with customers in order to improve it. Modern approaches and negotiating tactics are used. The analytical part of the chapter defines concepts such as business negotiation, communication process, business negotiator, customer and negotiating tactics. The application part of the chapter interprets results of research on behavior of customers and sale representative. To collect and analyze primary and secondary data, the questionnaire survey, controlled interviews and observing were used including own experience of the author of the chapter in communication with key customer during business negotiation. Proposals, recommendations and measures to improve the current situation were submitted. This was made in order to strengthen the current situation with customers/clients and to support creation of new business partnership which is based on trust, loyalty, satisfaction and interest of newly asked customers/clients who participate in the increase in demand on product/service.