LEWIS, J.S.C. (Delivering the Judgment of the Court): The appellants before us, Alitalia Airlines Ltd., are an Italian company having a branch in Nigeria and which operates the business of transport by air in many parts of the world including Nigeria. There had been correspondence between the appellants and the Chief Inspector of Taxes acting for the respondents, the Federal Board of Inland Revenue, about tax assessments on the Nigeria Branch of the appellants in respect of 1961/62 -1969/70 assessments and the Chief Inspector of Taxes had finally on the 5th of May, 1970 sent a letter of assessment in the following terms
"Gentlemen:
Alitalia Airlines Limited (Nigeria Branch)
1961/62 - 1969/70 Assessments
I refer to your letter of 7th April, 1970 in which you have proved that section 19(2) of the Companies Income Tax Act, 1961, is not applicable to the above-named client's case and have to detail hereunder the assessment basis of this Airlines Company for the years of assessment 1961/6…