Unjust enrichment in provisional assessment refunds does not apply retrospectively before the Rule 9B(5) amendment.

The doctrine of unjust enrichment was treated as inapplicable to refunds arising from finalisation of provisional assessments for periods before 25-6-1999, because the linking proviso to Rule 9B(5) of the Central Excise Rules, 1944 was inserted only by Notification No. 45/99-C.E. (N.T.) and was held not to operate retrospectively. Refund claims tied to pre-amendment provisional assessments were therefore outside the amended linking provision. The discussion also notes that the matter was regarded as the first valid finalisation order after withdrawal of an earlier order, so the cited Supreme Court observation on appeals against final orders did not control the refund claim.

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Issues: Whether the doctrine of unjust enrichment applies to refund arising on finalisation of provisional assessment for a period prior to 25-6-1999, and whether such refund is governed by the amended linking provision introduced later.

Analysis: The refund arose from finalisation of a provisional assessment relating to a period before 25-6-1999. The linking proviso to Rule 9B(5) of the Central Excise Rules, 1944 was introduced only by Notification No. 45/99-C.E. (N.T.) dated 25-6-1999, and the amendment was held not to be retrospective. On that basis, the doctrine of unjust enrichment was held inapplicable to refunds pertaining to provisional assessments for periods prior to the amendment. The case was also treated as the first valid finalisation order after withdrawal of the earlier order, so the bar in the cited Supreme Court observation on appeals against final orders did not govern the refund claim.

Conclusion: Unjust enrichment did not apply to the refund arising from finalisation of provisional assessment for the pre-25-6-1999 period, and the assessee's refund claim succeeded.

Ratio Decidendi: The doctrine of unjust enrichment applies to refunds arising from finalisation of provisional assessments only from the date the statutory linking provision comes into force, and it does not operate retrospectively to periods prior to that amendment.

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