Provisional assessment and unjust enrichment principles govern refund limitation and allow balance refund where duty incidence was not passed on.

Refund claims cannot be treated as arising from provisional assessment unless there is an express order or permission under Rule 9B; mere departmental correspondence, RT-12 endorsements, or a contractual price variation clause does not make the assessment provisional, so the claim remained subject to the refund limitation period and was time-barred for the delayed portion. On unjust enrichment, the escalation and de-escalation clauses in the purchase orders, together with deduction entries in payment advices, indicated that the duty incidence was not passed on to customers, so unjust enrichment did not bar the balance refund. The refund was therefore admissible only to the extent not defeated by limitation.

---

---

Issues: (i) Whether the refund claim was barred by limitation on the ground that the assessments were not provisional; (ii) Whether the refund was hit by the doctrine of unjust enrichment.

Issue (i): Whether the refund claim was barred by limitation on the ground that the assessments were not provisional.

Analysis: Provisional assessment requires an order or permission by the proper officer under Rule 9B; mere correspondence between departmental officers or an endorsement on RT-12 returns does not substitute such an order. A price variation clause in the contract does not by itself make the assessment provisional. In the absence of an express provisional assessment order, the refund claim had to comply with the limitation period for refund claims.

Conclusion: The refund claim was barred by limitation to the extent it related to duty paid beyond the prescribed six-month period; the issue was decided against the assessee on this aspect.

Issue (ii): Whether the refund was hit by the doctrine of unjust enrichment.

Analysis: The purchase orders contained escalation and de-escalation clauses, and the payment advices showed deductions towards excise duty difference. On that material, the incidence of duty was not shown to have been passed on to the customers. The doctrine of unjust enrichment therefore did not apply to the refundable excess duty.

Conclusion: The refund was not barred by unjust enrichment and was allowable to the assessee on this aspect.

Final Conclusion: The appeal succeeded only in part: limitation defeated the refund to the extent of the delayed claim, but the balance refund remained admissible because unjust enrichment was not attracted.

Ratio Decidendi: A refund claim cannot be treated as one arising from provisional assessment unless there is an express order under Rule 9B, and a contractual price variation clause alone does not displace the limitation under Section 11B; however, where the evidence shows that duty incidence was not passed on, unjust enrichment does not bar refund.

---