We present results of an electrochemical intercalation study of Zn into β-ZrNCl, β-ZrNBr and β-HfNCl. For β-ZrNCl an intercalation reaction takes place, leading to the final compound Zn 0 . 0 4 ZrNCl with a superconducting transition temperature T c of 15 K. A similar behaviour is observed for β-ZrNBr where the insertion reaction produces the superconducting compound Zn 0 . 0 4 ZrNBr with a T c of 14 K, whereas attempts to obtain Zn x HfNCl superconductors applying the same conditions failed. In comparison to β-MNX compounds with monovalent inserted ions, superconductivity in Zn doped β-MNX occurs at much lower levels of electron doping, although the values of T c are similar.