Reassessment for non-disclosure fails where family income facts were already before the tax officer and no material fact was withheld.

Omission to include a wife's or minor son's share income did not, on these facts, amount to failure to disclose fully and truly all material facts for reassessment under section 34(1)(a). The return requirement under section 22 concerned the assessee's total income, while the family income of the wife or minor child was relevant only at the computation stage under section 16(3). Because the family relationship and partnership facts were already before the Income-tax Officer at the original assessment, no material fact necessary for assessment was withheld. The reassessment notice and resulting assessment were therefore invalid in law.

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Issues: Whether the assessee's omission to include the share income of his wife and minor son in the return or assessment proceedings constituted a failure to disclose fully and truly all material facts necessary for assessment so as to justify reassessment under section 34(1)(a).

Analysis: The statutory scheme distinguished between the assessee's own total income and the inclusion of the wife's or minor child's income only at the stage of computation under section 16(3). The return under section 22 required disclosure of the assessee's total income, and the notes to the prescribed form did not clearly impose a statutory obligation to disclose the wife's or minor child's income as part of the assessee's own income. The assessment of a partner in a registered firm and the assessment of the firm were treated as complementary, and the relevant family relationship and partnership facts were already before the Income-tax Officer when the original assessment was made. On those facts, the material necessary for assessment was not withheld. Even on the assumption that the omission was a defect in the return, it did not amount to the kind of non-disclosure contemplated by section 34(1)(a).

Conclusion: The reassessment notice and the resulting assessment under section 34(1)(a) were not valid in law, and the assessee succeeded.

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