Microorganisms, genetically modified or not, may be used in the food chain as such or as production organisms of substances of interest. The placement of such microorganisms or derived substances/products in the European market may be subject to a pre-market authorization process. The authorization process defines the need to perform a risk assessment to establish the safety and/or the efficacy of the microorganisms when used in the food chain as such or as production strains of substances of interest. In order to perform a risk assessment, the microorganism/s subject to the application for authorization need to be characterized. In this regard, data obtained from whole genome sequence analysis can provide information on the unequivocal taxonomic identification of the strains and on the characterization of their potential functional traits of concern which may include virulence factors, resistance to antimicrobials of clinical relevance for humans and animals, production of known toxic metabolites. In fact, in some areas of the regulated products the use of whole genome sequence-based data has been established as a requirement for the risk assessment. This document provides recommendations to applicants on how to describe the process and results which should be provided to the risk assessor in the context of an application for market authorization of a regulated product. Indications are given on how to perform WGS and the quality criteria/thresholds that should be reached as well as the data and relevant information that need to be sent along whenever such kind of data is required.