Diplomatic tax refund entitlement conditioned on reciprocity, certification of official use, and compliance safeguards. United Nations and specified international organisations, and foreign diplomatic missions or consular posts and their diplomatic agents or career consular officers, are entitled to refund of State tax under section 55 of the Gujarat GST Act subject to conditions: certification by the organisation for official use; Protocol Division certificate based on reciprocity for missions; original undertaking for services that use is official or permitted personal; certificate for goods confirming mission use, prohibition on disposal for three years, and repayment obligation on non compliance; and withdrawal of Protocol certificate terminates refund entitlement.