[(NH2)3PNP(NH2)3]Cl has been prepared by a three step synthesis. The last step is the ammonolysis of [Cl3PNPCl3]Cl. Single crystals of 1,1,1,3,3,3-hexaamino-1λ5, 3λ5-diphosphazenium chloride were obtained from an acetonitrile solution in a temperature gradient between 60 °C and room temperature. Between room temperature and -100 °C [(NH2)3PNP(NH2)3]Cl is subject to a phase transition. Therefore, the crystal structure was determined by single crystal X-ray methods at room temperature (P1̄, a = 584.7(1) pm, b = 732.1(1) pm, c = 1092.0(2) pm. q = 71.05(3)°, β = 76.36(3)°, γ = 89.83(3)°, Z = 2, R = 4.75 %, wR = 2.47 %). The cation [(NH2)3PNP(NH2)3]+ is built up by two corner sharing PN4 tetrahedra. Remarkably short P-N bonding distances have been observed and both PN4 tetrahedra exhibit a significant distortion resulting in two large and four small N-P-N bond angles.