The assessee, a non-resident banking company, filed its return on the basis of Form No. 26AS available at the relevant time. On subsequent updation of Form No. 26AS, additional TDS entries were reflected and, during reconciliation, the assessee voluntarily furnished a revised computation before the issue of any statutory notice. The Tribunal held that the assessee had furnished a cogent and bona fide explanation, disclosed all material facts and placed on record the updated Form No. 26AS, reconciliation statements, TDS certificates and supporting documents. As the omission was inadvertent, no revenue loss had occurred since tax had already been deducted at source, and the case squarely fell within section 270A(6)(a). Accordingly, the penalty levied for under-reporting of income was deleted. (AY. 2020-21)