Final assessment order cannot be reopened by later demand notice once it attains finality and remains unchallenged.

An unchallenged final assessment order attains conclusive status, and revenue cannot reopen the assessment through a subsequent show cause notice for demand. Where the assessment had already adjusted excess duty against short payment and directed a separate refund claim for the balance, failure to challenge that order in the manner known to law deprived later demand proceedings of jurisdiction. The show cause notice and all consequential proceedings were therefore invalid, the confirmed demand could not be sustained, and the assessee succeeded.

---

---

Issues: Whether the revenue could sustain a show cause notice and demand after the final assessment order had attained finality without first challenging that assessment; and whether proceedings flowing from such notice were without jurisdiction.

Analysis: The final assessment order had adjusted the excess duty against short payment and directed a separate refund claim for the balance amount. That order was not appealed or otherwise challenged by the revenue and therefore attained finality. Once the assessment order became final, it was not open to the revenue to reopen the matter through a show cause notice for demand. In such a situation, the notice itself was without jurisdiction and all consequent proceedings could not survive. The reliance placed on the principles stated by the Supreme Court supported the conclusion that an appealable assessment order must be challenged in the manner known to law before any demand or refund issue can be pursued from it.

Conclusion: The show cause notice and all proceedings arising from it were invalid. The demand confirmed in the impugned order could not be sustained, and the appeal succeeded in favour of the assessee.

Final Conclusion: The order of the Commissioner (Appeals) was set aside and the revenue's demand failed because the unchallenged final assessment order had become conclusive.

Ratio Decidendi: A final assessment order that has not been challenged attains conclusive status, and a demand or refund dispute cannot be reopened through a subsequent show cause notice; any such proceedings are without jurisdiction.

---