The word, “assessment” used in the Income Tax Ordinance, 1984 means computation of the total income and determination of tax payable on such income. First all incomes shall for the purpose of charge of income tax and computation of total income, have to be classified and computed under the heads of income, namely, (a) salaries, (b) interest on securi­ties, (c) income from house property, (d) agricultur­al income, (e) income from business or profession, (f) capital gains and (g) income from other source under section 20. Income tax as one tax shall be payable on such total income. (63 DLR (2011) 308)

Assessment is really a matter of national revenue and the National Board of Revenue runs the show by issuing notifications etc time to time on the basis of broader guidelines promulgated in the Finance Act of a year. There should not be any doubt in the fact that every assessment either of income tax or VAT or excise presupposes existence of an order of asessment. It is equally true in the case of assessment of duty under the Customs Act. When no assessment assessing duty on the imported goods could be shown, only conclusion could be arrived at law is that there was no assessment. Any grievance raised or brought against such inchoate assessment must be held to be based on supposition of an assessment and does not deserve any consideration. Consequently, the rights and obligations arising out of assessment could only be agitated and decided only in accordance with law. High Court Division is generally not empowered to intervene in the process of assessment. ( Abul Khair Condensed Milk and Beverage Ltd. Vs. Commissioner of Customs and others, 2007, 36 CLC (HCD) [8525] )