The national marker is a unique chemical formulation added to all petroleum derivative fuels by their producers and importers in the amounts specified by the Energy Markets Regulation Agency (EPDK) prior to their commercial distribution. The purpose of the national marker is to prevent the circulation and distribution of illicitly obtained or smuggled fuels within national borders by making it possible to distinguish between legal and illegal fuels through detection of its presence or absence in fuel samples collected by law enforcement and regulatory authorities. The national marker has been in use since the beginning of 2007 when the directive on its use was implemented and it’s addition to a specific list of fuels became mandatory for distributors and refineries licensed by EPDK. The national marker was developed by TÜBİTAK UME and its formulation has been periodically updated to maintain the security of system. The infrastructure for the national marker was further developed through the development by TÜBİTAK BİLGEM of on-site control devices. In 2012, the Mobile National Marker Reference Device and the production of certified reference materials for the national marker were produced by TÜBİTAK UME and integrated into the system. Samples that are intitially analyzed with the on-site control devices are then sent for final analysis to Regional Reference Laboratories using measurement and analysis methods developed by TÜBİTAK UME. (In progress)