This guide has been developed to provide information about the solid biofuel Quality Assurance and presents a methodology that helps operators in the solid biofuels industry design an appropriate Quality Assurance system according to their demands. It acts as a supporting document for the application of the CEN/TS 15234 developed by CEN/TC 335. This guide is applicable for all operators dealing with solid biofuels within the scope of CEN/TC 335 from the following sources (CEN/TS 14961): - products from agriculture and forestry; - vegetable waste from agriculture and forestry; - vegetable waste from food processing industry; - wood waste, with the exception of wood waste which may contain halogenated organic compounds or heavy metals as a result of treatment with wood preservatives or coating, and which includes in particular such wood waste originated from construction and demolition waste; - fibrous vegetable waste from virgin pulp production and from production of paper from pulp, if it is co-incinerated at the place of production and heat generated is recovered; - cork waste.