The paper illustrates a proposition for process model of the P&I maritime insurance sale. A specific feature of such a form of insurance relates to the collaboration between an insurance company and P&I clubs, which insure shipping company liability. The paper shows a decomposition diagram of the process of P&I insurance sales, from the aspect of the insurance company. The process of insurance sale is described. For process specification, the following methods are used: Work Flow. Activity Flow and Data Flow Diagram. The first two methods clearly show the position of processes in organizational parts of the insurance company and external business organizations. The Data Flow Diagram shows processes and data flows between them, not depending on where these are performed or who performs them. Such a model is the basis for information system development.