Purpose The European Network of Biological and Physical Retrospective Dosimetry ‘RENEB’ has contributed to European radiation emergency preparedness. To give homogeneous dose estimation results, RENEB partners must harmonize their processes. Materials and methods A first inter-comparison focused on biological and physical dosimetry was used to detect the outliers in terms of dose estimation. Subsequently, trainings were organized to improve both tools dose estimation. A second inter-comparison was performed to validate training efficiency. Simultaneously, based on ISO standards, a QAandQM manual on all dosimetry assays was produced which states a common basis and harmonized procedures for each assay. The evaluation of the agreement of RENEB partners to follow the QAandQM manual was performed through a questionnaire. The integration of new members into the network was carried out in the same way, whatever the assays. Results The training courses on biological and physical dosimetry were judged to be successful because most of the RENEB members’ dose estimates improved in the second inter-comparison. The QAandQM manual describes the consensus for the minimum requirements and the performance criteria for both dosimetry assays. The questionnaire revealed that the whole network capacity currently can manage between 15 and 3800 samples once. Conclusion The methodology used to harmonize all dosimetry practice within the network RENEB was highly successful. The network is operational to manage a mass casualty radiation accident for immediate dose assessment. © 2016 The Author(s). Published by Informa UK Limited, trading as Taylor and Francis Group.