Valuation for duty
—(1) Where an instrument is chargeable with ad valorem duty in respect of —
any money expressed in any currency other than that of Singapore; or
any stock or marketable or other security,
the duty shall be calculated on the value, on the day of the date of the instrument, of the money in the currency of Singapore according to the current rate of exchange, or of the stock or security according to the average price thereof or, if there is no price, according to the value thereof.
(2) Where an instrument contains a statement of current rate of exchange or average price, as the case may require, and is stamped in accordance with that statement, it shall, so far as regards the subject-matter of the statement, be presumed, until the contrary is proved, to be duly stamped.
14. When interest or goods and services tax is expressly made payable by the terms of an instrument, the instrument shall not be chargeable with duty higher than that with which it would have been chargeable if no mention of interest or goods and services tax had been made therein.