Prospective operation of adverse customs circulars prevents retrospective additional duty recovery on previously exempt imported ore concentrates.

An adverse circular withdrawing the additional customs duty exemption for imported ore concentrates operates only prospectively, even if described as clarificatory. The earlier circular treated concentrates as "ore" and supported nil additional duty assessments. A later circular distinguishing ores from concentrates by reference to a Central Excise tariff manufacturing concept could not create retrospective customs liability for imports made before it was issued. The separate statutory fields of customs and central excise further preclude retrospective recovery based on that clarification. Accordingly, additional customs duty cannot be recovered for the period preceding the adverse circular.

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Issues: Whether the circular withdrawing additional customs duty exemption for imported ore concentrates could be applied retrospectively.

Analysis: The earlier circular treated ore concentrates within the expression "ore" for the applicable exemption, and the imported goods had consequently been assessed at nil additional duty. The subsequent circular distinguished ores from concentrates by relying on the manufacturing concept introduced in the Central Excise tariff and was used to demand duty for imports made before its issuance. A circular adverse to assessees, though described as clarificatory, operates prospectively; only a beneficial circular may operate retrospectively. The distinct statutory fields of customs and central excise also precluded retrospective financial liability on the basis of the later clarification.

Conclusion: The adverse circular could not be enforced retrospectively to recover additional customs duty for the period preceding its issuance.

Ratio Decidendi: An oppressive departmental circular imposing fiscal liability upon assessees is enforceable only prospectively, notwithstanding its purported clarificatory character.

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