The aim of this project is the upgrade of IT support of the Croatian Bureau of Statistics, Statistical Business Register (the SBR) the register for storing and managing information on enterprises, legal and local units in a manner adapted to the statistical surveys. This upgrade enabled information storage, registration and updating of data on enterprise groups to connect groups of enterprises with existing entities in the SBR. Also the information on the control relationships among various legal units is stored in the system which is a prerequisite for the process of profiling enterprise groups. User interface was designed and developed as web application (thin client) with extensive use of AJAX for improving user experience of the application. Business logic tier was developed using .NET framework and data tier was designed on the Microsoft SQL Server 2005.