Income-tax refund set-off and withholding powers apply against outstanding tax dues and pending assessment proceedings. Set off and withholding of refunds in certain cases under the Income-tax Act permit tax authorities to adjust a refund, or part of it, against any sum remaining payable by the taxpayer, after written intimation of the proposed adjustment. Where assessment or reassessment proceedings are pending, the refund may also be withheld for up to sixty days from the date of assessment or reassessment, but only for reasons recorded in writing and with the previous approval of the Principal Commissioner or Commissioner.