1-Hy-droxy-isoquinolin-2-ium hydrogen succinate

In the title salt, C9H8NO(+)·C4H5O4 (-), the isoquinolinium ring system is approximately planar [r.m.s deviation = 0.011 (2) Å]. In the crystal, adjacent cations and anions are linked by O-H⋯O and N-H⋯O hydrogen bonds, forming columns along the b axis. The columns are connected by weak C-H⋯O inter-actions into a three-dimensional network.