Call Center processing a large amount of customer contacts received via telephone is fitted out with appropriate technical equipment (e. g. sufficient number of telephone lines, HW and SW) as well as skilled and expertly trained call centre agents. According to a customer request, call center agents contact only certain group of customers. By this method, expenditure efficiency is constantly evaluated. Call center appears to be one of the most widely used and popular items which supports marketing and promoting campaigns. It also enables interaction through telephone channel and to affect directly desired group of customers. Skilled call center staff is here to carry out each task as it is requested by the client.