GISonLine, commissioned by Tauron, took part in the Marking and Supplementary Inventory project of MV poles and Transformer Stations. The project was based on the GRIDonLine Light platform. The tools provided by GISonLine were a Web and Mobile application. They made it possible to perform inventory by the field crews, more efficient work management, as well as storage and sharing the project documentation created. Thanks to the “Terrain” mobile application, users had the opportunity to perform an on-site inventory on a regular basis, which significantly reduced the number of errors related to following data transfer from paper documentation. An additional advantage characterising the projects carried out on the GRIDonLine Light platform, was the short application implementation time.