Summary:

According to the Council of Ministers regulation from 2000, new coordinate system "2000" should be applied in Polish official maps. Head Office of Geodesy and Cartography issued the rules of transformation between coordinate systems 1965 and 2000 which suggest using local corrective transformations. These guidelines are not obligatory. They allow to choose an optimal method according to the local conditions. In this article a few algorithms of local corrections were analyzed. Numerous tests based on real data from a few poviats were carried out to clarify the advantages and potential risks of all methods. Additionally, an influence of uncompleted data on final results was described.