An indium phosphate, [In-4(4,4'-bipy)(3)(HPO4)(4)(H-2-PO4)(4)] . 4H(2)O, prepared as single crystals under solvo-thermal conditions, has a new structure which consists of neutral sheets of indium phosphate linked through 4,4'-bipyridine pillars to generate channels in which water molecules reside. The structure of the anhydrous compound, In-4(4,4'-bipy)(3)(HPO4)(4)(H2PO4)(4), is also determined.