50. (1) The person responsible for making any payment which constitutes income of the payee classifiable under the head “Salaries” shall, at the time of making such payment, deduct tax on the amount so payable at a rate representing the average of the rates applicable to the estimated total income of the payee under that head.¹[(1A) Notwithstanding the provision of sub section (1), where any Government official is acting as Drawing and Disbursing Officer (DDO) or making or signing a bill for himself or for any other official subordinate to him to draw salary from the Government or any authority, as the case may be, he shall, at the time of making or signing such bill, deduct tax at a rate representing the average of the rates applicable to the estimated total income of such officials if such annual salary chargeable to tax exceeds the taxable limit for that income year.; এবং(1B) For the purposes of sub-section (1A), respective Government Accounts Office shall issue a tax deduction certificate in prescribed form within the thirty first day of July following the financial year. ] (2) At the time of making any deduction under ²[sub-sections (1) and (1A) ], the amount to be deducted may be increased or decreased for the purpose of adjusting any excess or deficiency arising out of any previous deductions or failure to make deductions.³[(2A) The payment under ⁴[sub-section (1) and (1A)] shall be made by such person with or without deduction of tax in accordance with a certificate, issued by the Deputy Commissioner of Taxes after being satisfied on an application made by the payee in this behalf, where such certificate specifies that-(a) no tax shall be deducted from the payee in a case where the tax payable on the total income of the payee has already been deducted or collected from such payee under this Ordinance for the rest of the income year; or(b) tax shall be deducted at a lesser rate for the rest of the income year in a case where the payee may, after adjusting the tax already deducted or collected from such payee under this Ordinance, be liable to pay a lesser sum of tax than the tax chargeable on his total income.] (3) For the purposes of deduction under ⁵[sub-section (1) and (1A)] in respect of salary payable in a foreign currency, the value in taka of such salary shall be calculated at such rate as the Board may prescribe.