2‐Amino­anilinium phosphite

The solid-state structure of the title compound, alternatively called 2-amino­anilinium hydrogen phosphonate, C6H9N2+·H2PO3−, shows the monoprotonated di­amine mol­ecule to be multiply hydrogen bonded to HPO3H− anions. There is no inter-phosphite hydrogen bonding, contrary to previous solid-state observations of the species.