The parent hexa-, hepta-, and octacoordinate boronium ions, BH6+ (1), BH72+ (4), and BH83+ (6), respectively, were found as stable minima by ab initio MP2/6-31G** and QCLSD(T)/6-311G** level of calculations. The C-2v symmetrical structure 1 with two 3c-2e bonds and C-3v symmetrical structure 4 With three 3c-2e bends an isostructural with their isoelectronic carbon analogues CH62+ and CH73+, respectively. Eight hydrogen atoms of T-d symmetrical structure 6 are bonded to the boron atom by four 3c-2e bonds. The protonation of BH5 to form BH6+ was found to be strongly exothermic. The reaction of BH4+ (3) and H-2 might be a suitable way to generate BH6+ (1) in the gas phase.