Since 1976, six national metrology institutes (NMI) and another laboratory have submitted eleven samples of known activity of Sc-46 to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM). The activities ranged from about 300 kBq to 6.9 MBq. The degrees of equivalence between each equivalent activity measured in the SIR and the key comparison reference value (KCRV) have been calculated and the results are given in the form of a matrix for six NMIs. A graphical presentation is also given.