Section 50C of the Income Tax Act

A proviso inserted into a section to remedy unintended consequences, make the section workable, or supply an obvious omission must be read retrospectively in operation to give effect to the section as a whole.

Section 14A cannot be invoked to disallow expenditure if the assessee has not earned any exempt income in the relevant assessment year. The Explanation to Section 14A is prospective in nature.

Amendments to the Income-tax Act that are curative, clarificatory, or beneficial in nature apply retrospectively from the date the original statutory provision was introduced, even if not explicitly stated.

Legislation is ordinarily presumed not to have retrospective operation, especially for taxing statutes unless explicitly stated or when intended to remove hardship for the assessee. The decision clarifies the principles for determining whether an amendment to a taxing statute applies prospectively or retrospectively, distinguishing between clarificatory and substantive amendments.

Once a claim for deduction under section 80-IA or 80-IB is allowed in the initial assessment year and is not subsequently withdrawn, the revenue is estopped from denying the deduction for subsequent years on the same grounds.

The Assessing Officer is duty-bound to refer the valuation of property to the Departmental Valuation Officer under Section 50C(2) when an assessee disputes the stamp duty valuation or if there is a discrepancy between the actual sale consideration and the guideline value. This reference is mandatory, even if not explicitly requested by the assessee, to ensure a realistic fair market value and avoid injustice.

Appellate authorities in income-tax proceedings have the jurisdiction and duty to correct all errors of lower authorities. They must remit matters for proper or fresh adjudication and issue appropriate directions to ensure substantial justice, unless expressly forbidden by statute.

Interest received on delayed payments for sales is considered part of the sale proceeds and is eligible for deduction under Section 80-IA as business income.

Curative amendments, such as a proviso to Section 40(a)(ia) introduced to remove undue hardship, apply retrospectively even without specific legislative declaration, rectifying shortcomings and obviating unintended difficulties.

Where the Assessing Officer performs an elaborate analysis to determine disallowance under Section 14A, the mere absence of a specific record of dissatisfaction with the assessee's calculation does not nullify the disallowance, provided the statutory steps are followed.