The bromine‐chlorine dianionic octahalide‐containing salts [C3(NEt2)3]2[Br4Cl4] (1c) and [C3(NEt2)3]2[Br3Cl5] (2d) were prepared using the triaminocyclopropenium cation as a template. The salt 1c was prepared in two steps, firstly, either by addition of BrCl to the triaminocyclopropenium chloride salt [C3(NEt2)3]Cl or addition of Cl2 to the bromide salt [C3(NEt2)3]Br to form the trihalide [BrCl2]– salt, secondly, addition of half an equivalent of Br2 gave the desired product upon crystallization at low temperature. Salt 2d is prepared by addition of excess BrCl to [C3(NEt2)3]Cl. Both salts are best described as two trihalides bridged by a dihalogen. When the tetraethylammonium cation is used, a salt of the formula [NEt4]2[Br4.56Cl0.44][ClBr2] (4), containing disordered [ClBr2]– and a chain of [ClBr4]– and [Br5]– pentahalides (in a ratio of 0.44 to 0.56, respectively). These interhalides were characterized by X‐ray crystallography, computational studies, Raman and Far‐IR spectroscopy, as well as by TGA and melting point.