This discussion addresses how to pay outstanding GST liability from FY 2018-19 where sales were declared in GSTR-1 but tax wasn't paid in the relevant GSTR-3B. The recommended approach is to use Form DRC-03, selecting 'voluntary' as the cause of payment. This ensures the purchaser can still avail Input Tax Credit (ITC), and the payment details will be reconciled in the annual return (GSTR-9C).