Businesses of roughly 300,000 firms paying goods and services tax (GST) were likely impacted on Monday, as the government had blocked e-way bill generation for non-compliant assessees. These businesses had not filed their monthly GST Return (GSTR)-3B for two consecutive months. The government had notified the rule last month as an enforcement measure amid subdued revenue collection. The GST system has been grappling with low levels of compliance. Only 65-68 per cent of eligible GST filers file the GSTR-3B within the due date, the GST Network (GSTN) data shows. “This month, the taxpayer will be alerted with a cautionary message while generating e-way bills, in case GSTR-3B for the past two successive months of the consignor/consignee GST identification number (GSTIN) has not been filed.