Kishan Das, Dhankutti, Kanpur. They were members of a joint Hindu family carrying on business until they became divided in the middle of assessment year 1953-54. Thereafter they were carrying on the business in partnership. For the year 1953-54, the firm submitted a retuni showing loss. But in the next succeeding year 1954-55 it disclosed a profit and submitted a return. All the four partners filed returns individually on 27-9-1954 and they were provisionally assessed on their returns on 14-10-1954. But the regular assessment was made for this year only on 27-2-1958. The firm continued to make profits in the subsequent years 1955-56, 1956-57, 1957-58 and 1958-59 and the partners filed returns for their income for each of these years and were regularly assessed for these years under s. 23 sometime after 27-2-1958. The assessment order for 1958-59 was in fact made on 19-2-1959. It is not disputed that none of the four partners sent any estimate of the tax payable on their income as required by section l 8A of the Income Ta"< Act, 1922 or pay the tax in advance. Therefore, the Income Tax Officer, Kanpur while assessing them under section 23 of the Act held that they were liable to pay interest under section I 8A ( 8) and determined the amount payable by each in respect of each of the years on the basis of the income found taxable in the regular assessment. In addition, he applied the provisions of section 18A(9)(b) and imposed a penalty for each year of assessment by virtue of section 28 read with section l8A(9) (b) of the Act. The four partners preferred appeals to the Appellate Assistant Commissioner on the ground that the levy of interest and penalty was unauthorised. But the appeals were dismissed. The partners applied in revision to the Commissioner of Income Tax under section 33A(2), but the revision applications were dismissed. The respondents thereafter moved the Allahabad High Court for grant of a writ to quash the orders of the Income Tax Officer and of the Appellate Assistant Commissioner in appeal. The applications for writ were allowed by Mr. Justice S. C. Manchanda who held that section 18A(3) could not apply to the facts of the> case as there had been a provisional assessment under section 23B in the year 1954. Against the decision of the Single Judge the appellants preferred appeals before the Division Bench. These appeals were dismissed hv a common judgment of the Allahabad High Court dated 25th March. 1963. The present appeals are brought to this Court by special leave from the judgment of the Allahabad High Court dated 25th March, 1963 in the batch of appeals affirming the judgment of the Single Judge dated 25th May, 1956 in C.W.M. No. 1591 <?f 1962 and the connected WTit applications.