The total revenue collected under GST fell by around 10 percent to Rs 83,346 crore for the month of October from over Rs 92,000 crore in September, official data showed.
The GST collection for the month of July was over Rs 95,000 crore, while for August, it was more than Rs 91,000 crore. September's indirect tax collection stood at over Rs 92,150 crore.
Commenting on the downward trend of tax revenue under GST, the government said it could be attributed to several factors including the fact that overall incidence of taxes on most goods had come down under the new tax reform.
"Since the overall incidence of taxes on most of the commodities has come down under GST, it would naturally have some implication on the revenues of the government.
"Since implementation of some of the main features of GST such as matching of returns, e-way bill as well as reverse charge mechanism have been postponed, the tax compliance may not be up to the mark," the statement from the Finance Ministry said.
Besides, because of the initial requirement of paying Integrated GST (IGST) on transfer of goods from one state to another state, there was an additional cash flow of IGST in the first 3 months.
"As and when the final transaction of these goods takes place, the credit for IGST is being utilized for payment of SGST and CGST and therefore, the inflow of new taxes is low," it said.
A senior Finance Ministry official said that while tax compliance may not be up to the mark, the numbers would improve as various features of GST, earlier postponed, are implemented.
The Ministry said that despite the shortfall, the states' revenues are fully protected taking base year revenue as 2015-16 and providing a projected revenue growth rate of 14 percent.
"The Central government has released a compensation of Rs 10,806 crore to the states for July and August, while a compensation of Rs 13,695 crore for September and October is being released," it said.
According to the data shared by the Ministry, a total of "50.1 lakh returns have been filed for the month of October till November 26, 2017".
Over 95.9 lakh tax payers have been registered under the GST so far, out of which 15.1 lakh are "composition dealers" who are required to file returns every quarter, it added.