Key indicatorsSingle-crystal X-ray study T = 296 K Mean (C-C) = 0.003 Å R factor = 0.027 wR factor = 0.076 Data-to-parameter ratio = 26.3For details of how these key indicators were automatically derived from the article, see

The crystal structure of the title compound, C5H6ClN2+·H2PO4−, can be described as a stacking of 3‐amino‐2‐chloropyridinium cations and dihydrogenphosphate anions. As well as electrostatic van der Waals interactions, the component species interact by means of multiple hydrogen bonds. The H2PO4− units are linked into polymeric chains propagating along the c axis by way of O—H...O hydrogen bonds. The organic cations are anchored between planes parallel to ac, linking the chains into a three‐dimensional network.