Prospective operation of taxing relief rule limits refund rights to transactions whose triggering event occurred after commencement.

Rule 12(1A) of the Bombay Sales Tax (Exemptions, Set-off and Composition) Rules, 1954 conferred remission or refund of purchase tax only when its statutory conditions were met, and the relief arose on a subsequent despatch to an outside address within nine months of purchase. A taxing rule creating a new relief or liability is construed prospectively unless its language expressly or by necessary implication provides otherwise. Because the rule contained no such indication, it did not extend to purchases and subsequent sales already completed before 1 March 1957. The reference to refund of tax already paid did not make the rule retrospective, and the refund claim would arise only where the triggering event occurred after commencement.

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Issues: Whether rule 12(1A) of the Bombay Sales Tax (Exemptions, Set-off and Composition) Rules, 1954 entitled a dealer to remission or refund of purchase tax where both the purchase and the subsequent despatch or sale occurred before the rule came into force.

Analysis: The rule created a right to remission or refund only when the statutory conditions were fulfilled, and that right arose on the occurrence of the subsequent despatch to an outside address within nine months from purchase. A taxing provision that affects existing liabilities or creates a new obligation is not to be given retrospective operation unless the language expressly so provides or necessarily requires it. The rule contained no express words or necessary implication extending the relief to transactions already completed before 1 March 1957. The reference to refund of tax already paid did not alter this position, because the rule could operate prospectively even where some antecedent event, such as the purchase, had occurred earlier; what mattered was that the event giving rise to the relief had to occur after the rule came into force.

Conclusion: Rule 12(1A) did not apply to purchases and subsequent sales both completed before its commencement, and the claim for remission or refund failed.

Ratio Decidendi: Unless the language of a taxing rule expressly or by necessary implication provides otherwise, it is construed prospectively, and a relief provision that creates a new right or obligation operates only when the event giving rise to that right occurs after commencement.

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