Mumbai - Demonetisation has benefited many government authorities which includes BMC, MHADA, BEST, ST, Municipal Corporation, etc. Stamp duty office and registration is bearing the brunt of demonetisation. Their collection has suffered a setback of 40% , informed Senior Inspector Registration office, N.Ramaswamy. Earlier over 6,000 documents were registered but the count has fallen up to 3,500. For every document individual has to pay Rs 20.