Reassessment substitutes original assessment, so revision limitation runs from the reassessment order under sales tax law.

Where reassessment under the Mysore Sales Tax Act substitutes the original assessment, the earlier assessment ceases to be operative and the reassessment becomes the fresh order for revision. The Supreme Court held that the four-year limitation for exercising revisional power under section 21(3) must be computed from the date of the reassessment order, not the original assessment order, because the reassessment is a comprehensive replacement rather than a mere addition. On that basis, the revisional orders were within time and the High Court's quashing of them was set aside.

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Issues: Whether, after reassessment under section 12A of the Mysore Sales Tax Act, 1957, the four-year period for exercise of revisional power under section 21(3) runs from the original assessment order or from the reassessment order.

Analysis: Once an assessment is reopened for escaped turnover, the original assessment ceases to be operative and is substituted by the reassessment order. The reassessment is a fresh and comprehensive assessment, not a limited addition to the original order. The revisional power under section 21(2) is therefore exercisable in relation to the reassessment order, and the limitation in section 21(3) must be computed from the date of that order. The absence of any statutory prohibition, unlike the provisions noticed in the income-tax enactments, supported this construction.

Conclusion: The four-year period under section 21(3) runs from the reassessment order dated June 8, 1966, and the revisional orders were within time.

Final Conclusion: The High Court's quashing of the revisional orders was set aside and the writ petitions failed.

Ratio Decidendi: Where reassessment substitutes the original assessment, the limitation for revising the assessment runs from the reassessment order because the earlier assessment no longer survives as the operative order.

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