Advance ruling clarifies binding scope and remedies for pre-transaction GST questions, subject to change for altered facts or fraud. Advance ruling permits a taxpayer to obtain pre-decision on tax consequences of proposed or ongoing supplies, covering classification, notification applicability, time and value of supply, input tax credit admissibility, tax liability, registration requirement, and whether an activity amounts to supply. State or UT Authorities act as the Authority for Advance Ruling for their territories; Appellate Authorities and a National Appellate Authority address appeals and inter-jurisdictional conflicts. Rulings bind only the applicant and concerned officer unless law, facts, or circumstances change; rulings obtained by fraud or misrepresentation may be void ab initio. Civil-court powers and a procedure for rectifying apparent errors are available, and rules prescribe filing formalities.