This work presents ongoing research in Pan-European Public Services (PEPS) and Pan-European E-Government Services (PEGS). This field of work is relatively new and has attracted the attention of the European Commission and of many research organizations and businesses as well. The semantic interoperability issues that may arise when a citizen of one Member State requests a public service from the public administration of another Member State are examined in this paper. The semantic conflict types that may arise in this case are identified and classified according to the Governance Enterprise Architecture (GEA) object model concepts. This conceptual modeling can be the basis for the building of a semantic gateway that will resolve these issues at a pan-European level.