GST collections to drop 20% in May due to state lockdown-like curfews, say experts SECTIONS Share Synopsis "With closed shops, businesses, supply-chain bottlenecks, restricted movements etc, tax collections are set to fall nationally by 10-20% in May, and for states like Maharashtra which is the highest contributor, the collections are likely to reduce by half,” said Harpreet Singh, indirect tax partner at KPMG India. Getty Images Goods and service tax (GST) collections could see a dip of 10-20% in May as Maharashtra - the largest state contributor to GST - and Madhya Pradesh enforce lockdown-like curfew rules even as other states have imposed night curfews to control the rising number of Covid cases.