A novel heteropolyanion-based sulfated ionic liquid (HIL[Ch-OSO3H](3)W-12 PO40) was prepared by pairing sulfate functionalized cholinium cation [N,N,N-trimethyl-2-(sulfooxy)ethanaminium] with catalytically active phosphotungstic acid anion (W12PO403-). It was characterized by H-1 NMR, EDX, XRD,TGA and elemental analysis. Catalytic activity of thus prepared HIL was studied in N-formylation of amines under solvent-free grinding condition. The methodology provided cleaner conversion over shorter reaction time with high turnover frequency (TOF) and chemoselectivity. (C) 2014 Elsevier B.V. All rights reserved.