Retrospective revision of approved excise classification lists is barred when the original approval was not challenged in time.

An approved excise classification list, if accepted and acted upon without timely challenge, cannot be revised retrospectively from the original effective date. A later request to alter the classification after the limitation period was ineffective because the earlier approval had attained finality. Where any revision is otherwise permissible, it operates only prospectively, not with retrospective effect. The rejection of relief was therefore consistent with the settled principle that an unchallenged approved classification cannot be reopened beyond limitation.

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Issues: Whether an assessee can seek retrospective revision of an already approved excise classification list after the approval has not been challenged within the prescribed limitation period.

Analysis: The approved classification list had been filed and accepted without change, and the assessee cleared goods on that basis. A later request sought to revise the classification retrospectively from the original effective date. The prior approval was never assailed by a timely appeal. In such circumstances, a challenge to an approved classification must be taken within limitation, and any revision, if permissible, operates only prospectively and not with retrospective effect. The appeal before the lower authority also sought relief on a basis different from the impugned approval, reinforcing the correctness of the rejection.

Conclusion: The retrospective revision of the approved classification list was not permissible, and the rejection of the appeal was correct.

Ratio Decidendi: An approved classification list, if not challenged within limitation, cannot be revised retrospectively; any permissible revision can operate only prospectively.

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