CRS transformations in North Macedonia: accuracy, offsets, and harmonization pathways

Abstract For over a century, North Macedonia has relied on coordinate reference systems (CRS) inherited from former Yugoslavia, resulting in inconsistencies between legal definitions, institutional practice, and usage. Despite several legal revisions, no comprehensive national framework has yet resolved these inconsistencies, leaving a critical research gap concerning the harmonization of CRS variants and their implications for interoperability. This study traces the historical development of CRS in the country, analyzes harmonization challenges, and compares regional transitions. Methodologically, the paper combines historical, legal, and technical analysis with comparative assessment of EPSG codes and transformation parameters, offering a systematic evaluation of CRS accuracy and offsets. Currently, three CRS variants (EPSG:6204, EPSG:6316, and EPSG:9945) coexist, producing offsets of 7,000 km in easting and 4,000 km in northing, which hinder GIS integration. Unlike neighboring states adopting ETRS89, North Macedonia lags behind. The findings highlight the need for an officially recognized transition toward an ETRS89-based CRS to achieve national and regional interoperability. Coordinated reforms, including EPSG registry recognition and transition to ETRS89, are essential for interoperability and reliable spatial infrastructure.