Section 44B of Income Tax Act "Special provision for computing profits and gains of shipping business in the case of non-residents"
44B. (1) Notwithstanding anything to the contrary contained in sections 28 to 43A, in the case of an assessee, being a non-resident, engaged in the business of operation of ships, a sum equal to seven and a half per cent of the aggregate of the amounts specified in sub-section (2) shall be deemed to be the profits and gains of such business chargeable to tax under the head "Profits and gains of business or profession".
(2) The amounts referred to in sub-section (1) shall be
the following, namely :-
(i) the amount paid or payable (whether in or out of India)
to the assessee or to any person on his behalf on account of
the carriage of passengers, livestock, mail or goods shipped
at any port in India; and
(ii) the amount received or deemed to be received in India
by or on behalf of the assessee on account of the carriage
of passengers, livestock, mail or goods shipped at any port
outside India.
Explanation.-For the purposes of this sub-section, the
amount referred to in clause (i) or clause (ii) shall
include the amount paid or payable or received or deemed to
be received, as the case may be, by way of demurrage charges
or handling charges or any other amount of similar nature.
What are Amounts not deductible? Section 40 of Income Tax Act 1961
What are Profits chargeable to tax? Section 41 of Income Tax Act 1961
Section 43AA Taxation of foreign exchange fluctuation
Section 43CB Computation of income from construction and service contracts
Section 44ADA Special provision for computing profits and gains of profession on presumptive basis