In the present case, GST liability arises on the basis of "time of supply" under Section 13 of the CGST Act, 2017. Since tax invoices have already been issued for the civil works services provided to the Irrigation Department during FY 2023-24, the supply stands completed and GST becomes payable irrespective of actual receipt of consideration. Accordingly, the entire taxable turnover relating to the invoices raised is required to be disclosed in GSTR-1 and GSTR-3B for the relevant tax period. Non-reporting of turnover merely because payment is pending from the Department may attract demand, interest and penal consequences under the GST law. It is pertinent to note that GST is payable on accrual basis and not on receipt basis, except in cases specifically covered under composition scheme or notified categories. Therefore, withholding of GST component by the Department does not defer or extinguish the statutory tax liability of the contractor. Further, if the Department has released only Rs. 60,00,000 without separately reimbursing GST, the contractor should immediately issue formal correspondence/legal representation demanding release of the withheld GST amount along with supporting invoices and contractual terms. The contractor may also verify whether any deduction has been made under Section 51 relating to TDS under GST. Hence, legally, the safer and compliant view is to declare the full invoiced turnover and discharge applicable GST liability, notwithstanding non-receipt of balance payment from the Department.