Article 31 - Unit of account of monetary unit and conversion

1. The unit of account referred to in article 18 of this Convention is the Special Drawing Right as defined by the International Monetary Fund. The amounts referred to in article 18 shall be converted into the national currency of a State according to the value of such currency on the date of the judgement or award or the date agreed upon by the parties. The value of a national currency, in terms of the Special Drawing Right, of a Contracting State which is a member of the International Monetary Fund, shall be calculated in accordance with the method of valuation applied by the International Monetary Fund, in effect on the date in question, for its operations and transactions. The value of a national currency in terms of the Special Drawing right of a Contracting State which is not a member of the International Monetary Fund shall be calculated in a manner determined by that State.

2. Nevertheless, a State which is not a member of the International Monetary Fund and whose law does not permit the application of the provisions of paragraph 1 of this article may, at the time of signature, ratification, acceptance, approval or accession, or at any time thereafter, declare that the limits of liability provided for in this Convention to be applied in its territory shall be fixed as follows: with regard to the limits provided for in paragraph 1 of article 18, to 13,750 monetary units per package or other shipping unit or 41.25 monetary units per kilogram of gross weight of the goods, and with regard to the limit provided for in paragraph 3 of article 18, to 124 monetary units.

3. The monetary unit referred to in paragraph 2 of this article corresponds to sixty-five and a half milligrams of gold of millesimal fineness nine hundred. The conversion of the amount referred to in paragraph 2 of this article into national currency shall be made according to the law of the State concerned.

4. The calculation mentioned in the last sentence of paragraph 1 of this article and the conversion referred to in paragraph 3 of this article shall be made in such a manner as to express in the national currency of the Contracting State as far as possible the same real value for the amounts in article 18 as is expressed there in units of account.

5. Contracting States shall communicate to the depositary the manner of calculation pursuant to the last sentence of paragraph 1 of this article, or the result of the conversion pursuant to paragraph 3 of this article, as the case may be, at the time of signature or when depositing their instruments of ratification, acceptance, approval or accession, or when availing themselves of the option provided for in paragraph 2 of this article and whenever there is a change in the manner of such calculation or in the result of such conversion.