Title II — TAX ON INCOME (3) International Carrier. — An international carrier doing business in the Philippines shall pay a tax of two and one-half percent (2 ½%) on its ‘Gross Philippine Billings’ as defined hereunder: (a) International Air Carrier. — ‘Gross Philippine Billings’ refers to the amount of gross revenue derived from carriage of persons, excess baggage, cargo and mail originating from the Philippines in a continuous and uninterrupted flight, irrespective of the place of sale or issue and the place of payment of the ticket or passage document: Provided, That tickets revalidated, exchanged and/or indorsed to another international airline form part of the Gross Philippine Billings if the passenger boards a plane in a port or point in the Philippines: Provided, further, That for a flight which originates from the Philippines, but transshipment of passenger takes place at any port outside the Philippines on another airline, only the aliquot portion of the cost of the ticket corresponding to the leg flown from the Philippines to the point of transshipment shall form part of Gross Philippine Billings. (b) International Shipping. — ‘Gross Philippine Billings’ means gross revenue whether for passenger, cargo or mail originating from the Philippines up to final destination, regardless of the place of sale or payments of the passage or freight documents. Provided, That international carriers doing business in the Philippines may avail of a preferential rate or exemption from the tax herein imposed on their gross revenue derived from the carriage of persons and their excess baggage on the basis of an applicable tax treaty or international agreement to which the Philippines is a signatory or on the basis of reciprocity such that an international carrier, whose home country grants income tax exemption to Philippine carriers, shall likewise be exempt from the tax imposed under this provision. (4) Offshore Banking Units. — The provisions of any law to the contrary notwithstanding, income derived by offshore banking units authorized by the Bangko Sentral ng Pilipinas (BSP), from foreign currency transactions with nonresidents, other offshore banking units, local commercial banks, including branches of foreign banks that may be authorized by the Bangko Sentral ng Pilipinas (BSP) to transact business with offshore banking units shall be exempt from all taxes except net income from such transactions as may be specified by the Secretary of Finance, upon recommendation of the Monetary Board which shall be subject to the regular income 32 Isla Lipana & Co., the Philippine member firm of the PwC network