The crystal structure of APA2[Zn3(HPO4)4(H2O)2] (APA = 2-amino-1-phenylene-ammonium, C6H9N2+) (1), as prepared by a predominantly non-aqueous synthesis, is described and compared to related compounds. 1 is built up from an alternating array of ZnO4 and HPO4 tetrahedra sharing vertices as Zn-O-P bonds to generate infinite anionic sheets. Within these sheets, polyhedral 4-, 6- and 8-rings are apparent. The negative charge of the inorganic layer is balanced by singly-protonated APA template cations and water molecules are also present. The components are linked by Nt-H⋯Of, Of-H⋯Ow, Ow-H⋯Of and Of-H⋯Nt (t = template, f = framework, w = water) hydrogen bonds: The last of these represents an unusual framework-to-template interaction. Weak Ct-H⋯Of links may also play a role in consolidating the structure. Crystal data: 1 (C12H26N4O18P4Zn3), Mr = 834.36, monoclinic, C2/c (No. 15), Z = 4, a = 20.194 (8) Å, b = 8.682 (3) Å, c = 15.123 (6) Å, β = 91.510 (11)°, V = 2650.5 (17) Å3, R(F) = 0.048, wR(F2) = 0.112.