Refund of integrated tax on exports requires shipping bill, valid GSTR-3B and customs confirmation before electronic credit. The shipping bill is deemed to be an application for refund of integrated tax on exported goods only after filing of the departure/export manifest, transmission of export invoice details via FORM GSTR-1 and furnishing a valid FORM GSTR-3B return; Aadhaar authentication is required where prescribed. Upon confirmation of a valid return, the customs-designated system or proper officer processes the claim and credits the integrated tax paid to the exporter's registered bank account. Refunds may be withheld on commissioner request, Customs violation findings, or risk-based verification, and withheld claims are transmitted electronically as system-generated FORM GST RFD-01 to the appropriate tax officer and processed under rule 89.