Distinct customs assessment regimes: final assessment under one provision cannot be converted into provisional assessment under another.

Section 29A of the Sea Customs Act applies to assessment on the bill of entry before examination of goods, with re-assessment only if the stated facts are later found untrue, while Section 29B governs provisional assessment where full information is unavailable, further proof is needed, or testing is required at the outset. The provisions operate in different factual settings and create distinct procedures, so the presence of non obstante language does not justify converting a final assessment under Section 29A into a provisional assessment under Section 29B. The text also notes that short-levy recovery could still be pursued under Section 39.

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Issues: Whether an assessment made under Section 29A of the Sea Customs Act could subsequently be converted into a provisional assessment under Section 29B, and whether those provisions were mutually exclusive or complementary.

Analysis: Section 29A contemplated assessment on the basis of the bill of entry before examination of the goods, with re-assessment only if the statement on which the assessment rested was later found to be untrue on examination of the goods or otherwise. Section 29B, by contrast, applied where provisional assessment was justified at the outset because the importer lacked full information, further proof was required, or a test was necessary. The two sections thus operated in different factual situations and embodied distinct procedures. The presence of non obstante language in both provisions did not permit the authorities to mix them or convert a final assessment under Section 29A into a provisional assessment under Section 29B. The machinery for recovery of short-levied duty also existed under Section 39, so the department was not left without a remedy.

Conclusion: The conversion of the assessments from Section 29A to Section 29B was not lawful, and the contention that the two provisions were interchangeable was rejected.

Final Conclusion: The appeals succeeded, the impugned orders were set aside, and the Customs authorities were left to proceed only on the footing of a Section 29A assessment.

Ratio Decidendi: A statutory assessment made under a provision treating the assessment as final, subject only to later re-assessment on proof of falsity, cannot be converted into a provisional assessment under a separate provision enacted for cases where provisional assessment is justified from the outset.

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