Documentary evidence for GST refund: prescribed attachments and declarations under prescribed rule determine admissibility of refund claims. Refund applications under Section 54(4) must include prescribed documentary evidence under Rule 89(2) (Annexure 1 to Form GST RFD-01) to establish entitlement and evidence or declarations on whether tax incidence was passed on. Category-specific attachments are required for exports of goods, exports of services, electricity exports, upward price revisions (with supplementary invoices, bank realisation/FIRC and reconciliation), SEZ supplies, deemed exports, inverted duty credit claims, provisional assessments, tax allocation changes, excess payments, and refunds claimed by unregistered persons.