Rectification cannot reopen a concluded assessment on a new theory or change of opinion under sales tax law.

Rectification under section 37(1) of the Assam General Sales Tax Act, 1993 is confined to arithmetical or other factual mistakes apparent from the record and cannot be used to reopen a concluded assessment on a fresh interpretation or a matter requiring investigation or proof. Where the original assessment was made after scrutiny of accounts and records, a subsequent notice based on a new base-year production theory was not an apparent mistake but a re-argument on merits and a change of opinion. The rectification and revisional orders were therefore without jurisdiction and liable to be quashed.

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Issues: Whether the power of rectification under section 37(1) of the Assam General Sales Tax Act, 1993 could be used to reopen a concluded assessment on the basis of an alleged mistake not apparent from the record.

Analysis: The rectification provision was confined to arithmetical mistakes or other factual mistakes apparent from the record. A concluded assessment could not be revisited on the basis of a fresh reasoning, a new interpretation, or a matter requiring investigation, argument, or proof. The original assessment had been completed after scrutiny of the accounts and records, and the impugned notice and orders proceeded on a new basis of base year production, which was not shown to be an apparent mistake on the face of the record. Such an exercise amounted to re-argument on merits and a change of opinion, which fell outside the scope of section 37(1).

Conclusion: The rectification and revisional orders were without jurisdiction and were liable to be quashed.

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