The paper deals with the evaluation of internal communication in company. Functional communication system is a competitive advantage because it increases the flexibility of the company and its customer service. Communication audits are conducted in various ways in practice. However, the sticking point is to collect data in a form to allow set firm conclusions and providing possibilities for their optimization either. Therefore, it is necessary to correctly define the relevant requirements for measuring and subsequent evaluation of the data obtained on the communication flows. These data can then be further analysed and processed for example, through statistical methods. Proposal requirements in article is elaborated on the analysis of current approaches to given issue in the Czech Republic and abroad, logical deduction, as well as comparisons with quality requirements by the standards of ISO 9000.