The Institute for Reference Materials and Measurements (IRMM) of the Joint Research Centre (JRC) of the European Commission (EC) is one of the reference materials producers which certifies reference test pieces for the indirect verification of Charpy pendulum impact machines. The certification approach taken at IRMM consists of two main steps. In a first step, a Master Batch of reference test pieces is certified for each of a number of chosen nominal energy levels (currently 30 J, 60 J, 80 J, 120 J, and 160 J). The certified absorbed energy value of these Master Batches is determined in an international round-robin. In the second step of the certification process, the Master Batch test pieces are used to determine the certified value of Secondary Batches of reference test pieces of the same nominal energy. This is achieved by comparing samples of Master and Secondary Batch under repeatability conditions. In this paper, this Master Batch — Secondary Batch approach is critically assessed in terms of traceability and uncertainty of the certified absorbed energy. It is shown that the produced reference test pieces are fit-for-purpose: they meet the requirements of their intended use (indirect verification).