Finality of unchallenged assessment orders bars collateral attack in recovery proceedings, even after later clarificatory rulings.

An appealable assessment order fixing annual capacity and duty liability attains finality when no statutory appeal is filed, and its correctness cannot be questioned collaterally in recovery or execution proceedings. A later Supreme Court ruling treating exclusion of gallery length as clarificatory and retrospective did not permit reopening a concluded assessment, because the dispute was not a pure jurisdictional nullity but an alleged error in determination. The settled principle applied was that an unchallenged assessment order remains binding and the assessee cannot resist recovery on that basis.

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Issues: Whether an assessee can dispute the duty liability fixed by an unchallenged assessment order in recovery proceedings on the strength of a later Supreme Court decision.

Analysis: The order determining annual capacity and duty liability was appealable, but no statutory appeal was filed against it. The writ petition filed against that order was dismissed as withdrawn. The later Supreme Court decision on exclusion of gallery length was held to be clarificatory and retrospective, but that did not permit reopening a concluded assessment in proceedings in the nature of execution. The settled rule applied was that an appealable assessment order, if not challenged in the manner known to law, attains finality and its correctness cannot be questioned collaterally in refund or recovery proceedings. Only a pure jurisdictional nullity can be raised otherwise; an alleged error in determination does not suffice.

Conclusion: The assessee could not resist recovery by challenging the unappealed assessment order, and the duty demand was upheld.

Final Conclusion: The appeal failed because the assessment order had attained finality and the short-paid duty was recoverable notwithstanding the subsequent clarification of law.

Ratio Decidendi: An appealable assessment order that is not challenged in accordance with the statutory procedure attains finality and cannot be reopened or collaterally attacked in proceedings for recovery or execution, except on the ground of lack of jurisdiction.

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