GST invoice compliance: require correct GSTIN, tax type and recipient details to secure consuming State revenue. Departments and designated deductors must award contracts only to suppliers with valid GSTIN and, before making payments, ensure tax invoices record supplier GSTIN, tax type (intra state or IGST), State code and recipient address; Transport Department must refuse registration of out of State vehicle purchases absent invoices showing supplier GSTIN, IGST and recipient State code. Deductors must obtain TAN, departmental email, valid PANs for DDOs and PAN linked Class II/III DSCs; the GSTIN registration window for TDS will open and the effective date for GST TDS will be notified.