A unique nickel-based catalytic system was developed where the direction of the hydrophosphorylation reaction can be controlled by varying the catalyst loading. A flexible one-pot access to vinylmonophosphonates and alkylbisphosphonates was demonstrated using simple starting materials in an atom-economic reaction without any specific solvents or ligands. Monitoring of the reaction mechanism with joint NMR and MS studies revealed key infor-mation about the reaction intermediates. The synthetic scope of the developed catalytic system was explored and the utility of the synthesized products for the fire protection of cotton materials was demonstrated.