► Synthesis of sulfonylamidophosphates and their sodium salts. ► Characterization of the synthesized compounds by IR, 1H, 31P NMR spectra. ► Structural investigations of three of the synthesized compounds. Sulfonylamidophosphates with formula PhSO2NHP(O)(OR)2 (HL1: R=PhCH2; HL2: R=p-MeC6H4) and (p-C6H4SO2NHP(O)(OMe)2)2 (H2L3) were synthesized via a three-step procedure based on Kirsanov reaction. Sodium salts NaL1, NaL2 and Na2L3 were prepared from the corresponding sulfonylamidophosphates to explore their acid nature of the imide nitrogen. The products were characterized by means of 1H, 31P NMR and IR spectroscopies and elemental analysis. Crystal structures of HL2, H2L3 and NaL2 were determined using X-ray crystallography. HL2 produces a dimeric aggregate via intermolecular hydrogen bonding. In contrast, H2L3 and NaL2 form 1D polymeric chains.