EN
Development of international trade and import/export processes is crucial to economic growth and GDP of Poland but it also commits to apply standards of international transactions. Interoperability in EU Digital Single Market determines participation of polish enterprises and public administration in European public procurement market. Lack of organizational and technological e-readiness according to European Norm of e-invoicing in cross-border transactions is a barrier to European community trade and a reason of low competitiveness of polish entities on EU market. Only 1% of invoices traded in Poland (ranked as 16 in EU) have format of standardised and structured e-document enabling automation of data processing. Lack of standardization and digitization of end-to-end public procurement in Poland causes lower efficiency of participants. The solution to researched problem presented in this article concerns implementing universally accessible, domestic e-invoicing system in Poland that fulfils requirements of e-invoicing European Norm according to Directive 2014/55/EU of the European Parliament and the Council on electronic invoicing in public procurement. Process and service oriented architecture of e-invoicing system has to integrate pre-award and post-award phases of complete end-to-end procurement process. An e-invoicing information system comprises of: layer of e-documents exchange web services, e-repository of e-document schemas, e-archive of e-documents, integration interfaces with conversion maps and validation formulas assuring interoperability of e-procurement participants. Proposed e-invoicing system assures normalization of public procurement cooperation and invoicing transparency of public funds, e-payment services and business policy of public funds transfer. The results of public e-procurement simulation's costs analysis indicate significant improving of costs efficiency both enterprises (61,90%) and public administration (80,49%).