The optimisation and the resources saving can represent an economic lever and support companies' competitiveness. In Italy, the national government has established a strong policy for energy saving, energy efficiency and for incentives to energy production from renewable sources, whereas polices and tools for improving resource efficiency have not been developed yet. The purpose of this work is to present an operational methodology, developed by ENEA, for the audit of resources at the company level, with the aim to boost resource efficiency, thus obtaining both economic and environmental advantages. This methodology operates both internally, by means of an efficiency increase and processes optimisation, and externally, by means of the cooperation with other companies and stakeholders at territorial level (industrial symbiosis). The proposed resources audit is based firstly on the analysis of input and output resources used and produced by a company and then on the investigation of possible options to reduce their consumption or under-utilization (waste disposal, etc.).