Even as the goods and services tax (GST) revenue is trailing, the long-delayed comprehensive returns-filing system won\u2019t come into effect even from January 1, the date announced for its launch after a high-level panel mooted a simplified format for such returns, but only from next fiscal. The triplicate return forms \u2014 that include the summary return and forms for inward and outward supplies \u2014 will be rolled out only from April 1 2019, new revenue secretary Ajay Bhushan Pandey said on Tuesday. Although the government is keen to implement a system that would be better at tracking evasion through matching of invoices, it is also wary of the repeat of earlier experience when the system would frequently break down due to glitches when it tried rolling out the triplicate-returns system. The GST Council had to suspend the original triplicate forms in November last year after assessees complained of its cumbersome nature and glitch-prone functioning. Since then GST returns filing has been confined to the summary returns GSTR 3B (with which taxes are paid) and outward supply (GSTR- 1). In the absence of inward supply returns, the crucial anti-evasion requirement of invoices-matching is not being met. It is assumed this is one of the reasons for the continuing shortfall in GST collections. As FE had reported in August, the government wanted to avoid implementation of the new system without completing the elaborate testing procedures to make the system foolproof. The new system promises to generate monthly returns automatically based on supply data uploaded by an assessee. Based on the Centre\u2019s budget estimates of CGST, IGST and compensation cess and assuming SGST to be equal to CGST minus budgeted compensation cess proceeds, the total GST collections required to meet the target is `12.57 lakh crore, or about `1.05 lakh crore a month. Against this, the average collection in April-November period was just `97,050 crore. This would mean that in the last four months of the fiscal, the total GST collections (Centre plus states) should be `4.8 lakh crore, or `1.2 lakh crore\/month to meet the estimates. However, there has been a surplus of about `4,160 crore a month in the compensation pool in the April-September period. Since the Centre can lay its hands on half of this surplus amount, a little over `2,000 crore a month it could get from this route (assuming the surplus generation will be at the same level for H2). That still leaves monthly GST collections of `1.18 lakh crore for the rest of the fiscal. It is another matter the states\u2019 shortfall (from 14% annual growth) will be bridged through the compensation mechanism. \u201cWe are short by `4,000 crore this month (November). But we are confident that we will be able to achieve our target. Our monthly target has been around `1 lakh crore. This we want to increase to `1.1 lakh crore (for the last four months of 2018-19),\u201d Pandey said. GST collection in November was `97,637 crore.