The public utility company "Infostan tehnologije" is part of the utility system of the City of Belgrade, whose activity is the unified collection of utility services. The method of unified billing (SON) of communal services in Belgrade was established on January 1, 1977. The price is determined by public companies that deliver their services to users and the Assembly of the City of Belgrade, which gives consent to price changes. At the same time, PUK "Infostan tehnologija" only makes the payment. There are currently more than 800,000 users in the unified billing system.