The Chambers of Commerce and Industry of the Spanish city of Castilla y Leon, in collaboration with the Ministry of Environment of Caja Duero, have published a 187-page guide for businesses to help them meet their reporting obligations under the European Pollutant Release and Transfer Registers (PRTR) Regulation. The guide addresses the regulatory framework of the Register, obligations and activities involved, production capacity thresholds, general data reporting, and data processing of transmitted information, with sector-specific examples, simulations and further information on the systematic reporting of releases and transfers to the PRTR Register of Castilla y Leon. The Chambers, in addition to providing this guide to businesses, are organizing in the framework of the Environmental Forum a conference-workshop with the goal of providing free advice about businesses their obligations, the data subject to notification, and use of the application of electronic platform that will facilitate reporting in Castilla y Leon. The Guide can be downloaded in pdf format at: www.camaradeavila.com. In Spanish.