In the anion of the title salt, C(6)H(16)N(+)·C(18)H(13)O(8) (-), one of the carboxyl groups is deprotonated. Its O atoms are involved in inter-molecular hydrogen bonding with the carboxyl group of an adjacent anion and the amino group of an adjacent cation. The two benzoyloxy rings are oriented with respect to each other at a dihedral angle of 79.46 (6)°.