DONE at Vienna, this day of eleventh day of April, one thousand nine hundred and eighty, in a single original, of which the Arabic, Chinese, English, French, Russian and Spanish texts are equally authentic.
IN WITNESS WHEREOF the undersigned plenipotentiaries, being duly authorized by their respective Governments, have signed this Convention.
Chronology of development of the Testimonium: Authentic languages clause at the 1980 Vienna Diplomatic Conference
Scholarly writings on this subject
Comments on Testimonium by Malcolm Evans in 1987 Bianca-Bonell Commentary on the International Sales Law
Harry M. Flechtner [U.S.], excerpt from The Several Texts of the CISG in a Decentralized System: Observations on Translations, Reservations and other Challenges to the Uniformity Principle in Article 7(1), 17 Journal of Law and Commerce (1998) 187-217
EDITOR: Albert H. Kritzer
The CISG comes in six equally authentic texts. The CISG has also been translated in still other languages.
In "Uniform Statutes in English law," Mann calls attention to the use of texts in languages other than one's own as an aid to understanding legislative intent and the manner in which contracting parties understood the text. He states:
"It is now established that for the purpose of ascertaining the ordinary meaning of a uniform statute it is legitimate to refer to a foreign text irrespective of whether it is the only authentic one upon which the English text is based or whether its authenticity is equal with that of the English text. . . .
"What is not yet clear is whether an English court is permitted to look at texts translated into other languages. Thus [in considering the Convention on the Contract for the International Carriage of Goods] it would hardly be open to doubt that the German counterpart of the English phrase "charges incurred in respect of the carriage of good," viz. the words "sonstige aus Anlass der Beförderung des Gutes enstandene Kosten" cannot reasonably be understood as including excise duties; the same would probably apply to the Dutch word "vervoerskosten" which Lord Wilberforce referred to as part of a decision of the Amsterdam court rejecting the carrier's liability for excise duty. It is submitted that a translated text is a permissible and frequently a suseful guide to decision, for it is likely to indicate how one of the High Contracting Parties understood the authentic text."
Discrepancies in translation can arise whenever there are multiple texts. Article 33 of the 1969 Vienna Convention on the Law of Treaties seeks to aid in the resolution of such problems by calling for "the meaning which best reconciles the texts, having regard to the object and purposes of the treaty;" but one can encounter translated words that have different meanings which are difficult to reconcile.
See, for example, "essentielle" in the French text and "substantial" in the English text -- words which can have different meaning in the context of CISG Article 3(1), particularly where, as pointed out by Flechtner, " 'substantielle' was available to the drafters of the French text."
In a similar vein, Barrera Graf refers to the translation of the Convention into Spanish as "not always a happy one".
Goode notes "the extreme difficulty not only in translating concepts that have no exact legal equivalent in the other system but also in converting the structure and syntax of one language into the quite different structure and syntax of another. This can lead to an unenviable choice between precise adherence to the original text in the translation, with the risk that the rendering of the translation is inelegant or out of harmony with linguistic usage, or freer rendering which responds to the structure and usage of the second language but at the sacrifice of legal accuracy."
Kastely states, "[W]ords used in one language . . . carry implications different from those in another . . . The terms 'offer' and 'acceptance' provide powerful examples of this. In English these words carry a rich heritage of legal doctrine, and their equivalents in the Western European languages have similar depth . . . Yet the translations of these words used in the other official versions, such as Chinese and Arabic, do not carry similar implications. . . ."
"If there are several, equally authentic texts of a multilingual convention, it is questionable for an autonomous interpretation to let some languages prevail over others simply because of practical reasons as with the CISG, where there are as many as six languages involved. . . . As the 'international legislator' declares, since all these languages are equally authentic, no language may prevail. A lawyer must find the accurate text ("texte juste") by comparing them all.
"If such a comparison reveals disparities between the authentic texts that cannot be rectified, then the interpretation rule in article 33 of the 1969 Vienna Convention on the Law of Treaties has to be applied which provides that the real or normative intention of the final diplomatic conference is decisive. . . . The intention of the international legislator in the final diplomatic conference can be found by way of a historical interpretation of the travaux préparatoires. . . ."
As the basis for an autonomous interpretation, "it is reasonable to examine the English and French texts of the CISG to find a texte juste, because these were the languages in which the deliberations and legal negotiations among the representatives of the Contracting States took place. It can be presumed then, that the English and French texts of the CISG best represent the intentions of the representatives at the 1980 Diplomatic Conference in Vienna as to the exact wording of the Convention's final text. . . ." (citations omitted) 
Similarly, Schroeter states:
"[T]he English language was the one primarily used during the discussions in Vienna and, maybe more importantly, the only language used by the Diplomatic Conference's drafting committee which produced the final text of the provisions. The Convention's English text version should therefore, in this author's opinion, and based on Article 7(1) CISG, be accorded prevalence where it is in conflict with other language versions, as the latter are sometimes not more than less-than-accurate translations of the English version." (citations omitted) 
And guidance contained in the Third (English) Edition of the Schlechtriem & Schwenzer Commentary on the UN Convention on the International Sale of Goods (CISG) is to the following effect.
"All the language versions are in principle equally authentic for the application of the Convention. That also follows from Article 33 of the Vienna Convention on the Law of Treaties. In so far as discrepancies arise in individual cases, they are to be solved by reference to the travaux préparatoires and the circumstances of a treaty.s conclusion (Articles 33(4), 32 of the Vienna Convention on the Law of Treaties). In addition, Article 7(1) requires to take account of the prevailing understanding in order to promote the uniformity in the CISG.s application. As a rule the English, and occasionally the French, text will have to be given precedence, because drafting was carried out almost exclusively in those languages. If the discrepancy cannot be settled, the treaty is to be interpreted according to its object and purpose (Article 33(4) of the Vienna Convention on the Law of Treaties." (citations omitted) 
Parties may wish to include in their contracts a language clause, for example, "The applicable text of the Convention shall be the official United Nations text in the language in which this contract is written."
Honnold adopts Mann's approach to ascertaining legislative intent in the context of "place of business". He cites the use of "etablissement" and "establecimiento" in the official French and Spanish texts of the CISG as authority for the position that a temporary stopping place should not be regarded as a place of business. John O. Honnold, "Uniform Law for International Sales Under the 1980 United Nations Convention", 2d ed. (Kluwer 1991) 79.
On the other hand, there was at one time a proposal to restrict the definition of relevant place of business to a place at which a party "maintains a permanent organization". This proposal was not adopted. UNCITRAL Yearbook II, A/CN.9/SER.A/1971, page 54, para. 28. Similarly, the delgates to the 1980 Vienna Diplomatic Conference elected not to adopt an ICC recomendation that it "be made clear in [article 10] that for a place to be a place of business, a permanent business organization, including a physical location and employees for the sale of goods or services should be maintained." UN Doc. A/CONF.97/19 (1981) 73. One should also recognize that there are instances in which for certain purposes, e.g., tax jurisdiction, temporary stopping places have been held to be "permanent establishments". A related issue is whether the presence of an agent with powers to conclude a sale could be regarded as a "permanent establishement" as is the case under many tax treaties. UNCITRAL Yearbook VIII (1977), A/CN.9/SER.A, page 146. See also Mann who comments upon "judicial diversification" in the context of "the conception of 'place of business' in article 28 of the original Warsaw Convention which deals with jurisdiction at the option of the plaintiff." He states, "The question whether that expression, being a translation of the French 'etablissement', comprises another airline or a mere travel agency which issues the ticket, provoked numerous decisions, particularly in England, France and the United States of America. No uniform practice developed. The results were in 1976 carefully compiled by the Federal Supreme Court of Germany which felt able to avoid a decision. Yet it arrived at the surprising result that a ticket of the Bulgarian airline which had been issued by the Deutche Lufthansa in Germany where the Bulgarian had a 'station' enabled the plaintiff to bring his action in Germany. Since the 'station' of the Bulgarian airline had no contact with the plaintiff or, indeed, the public and seems to have carried out purely internal operations, the decision may go much further than most others. F.A. Mann, op cit. 391-392 [citation omitted].
3. Harry M. Flechtner, "The Several Texts of the CISG in a Decentralized System: Observations on Translations, Reservations and other Challenges to the Uniformity Principle in Article 7(1)", 17 Journal of Law and Commerce (1998), text accompanying note 14. Flechtner's context is the use of "substantial" in the English text and "essentielle" in the French text of Article 71(1).
4. For concerns that follow from this, see Jorge Barrera Graf, "The Vienna Convention on International Sales Contracts and Mexican Law: A Comparative Study", 1 Arizona Journal of International and Comparative Law (1982) 142 n.117, 143 n.121, 149 n.178.
7. Frank Diedrich, "Maintaining Uniformity in International Uniform Law via Autonomous Interpretation: Software Contracts and the CISG, 8 Pace International Law Review (1996) 317-318. His note 76 states1: "One German author pointed out that the negotiations within the drafting committee of the 1980 Diplomatic Conference were exclusively done in English and that, therefore, in cases of doubt, the English text should prevail. See von Caemmerer & Schlechtriem-Herber, [Kommentar zum Einheitlichen UN-Kaufrecht, 2d ed. (Beck 1995)], art. 7, no. 22; see also . . . Ulrich Magnus, Das UN-Kaufrecht tritt in Kraft, 52 RabelZ 123, 128 (1987) (underlying the practical importance of the English version of the CISG because of the many legal similarities it has with the legal terminology of common-law countries.)" See also the comments to the same effect in the "Notes for Authentic Text and Witness Clause" section of the 2008 UNCITRAL Digest of Case Law on the United Nations Convention on the International Sale of Goods, where it is stated: "Schlechtriem makes the argument for using the English (and French) text to resolve discrepancies in different language versions at p. 21 (Intro to art. 1-6, paras 29 & 30) and on p. 940 (Witness clause discussion para 4)." 2008 United Nations Publication Sales No. E.08.V.15, page 294. This approach has been endorsed by the Federal Supreme Court of Switzerland. The court stated:
"The UN Sales Law was drafted in Arabic, English, French, Spanish, Russian and Chinese. ... In the case of ambiguity in the wording ... the English version, and secondarily, the French version are given a higher significance as English and French were the official languages of the Conference and the negotiations were predominantly conducted in English (Witz, in International Einheitliches Kaufrecht, Praktiker-Kommentar und Vertragsgestaltung zum CISG by Witz / Salger / Lorenz, Art 7 CISG, para. 20; Achilles Kommentar zum UN-Kaufrechtsübereinkommen (CISG), Art 7 CISG, para 4; cf. also Siehr, in Honsell (ed), Kommentar zum UN-Kaufrecht, Präamble, para. 6; Ferrari, in Schlechtriem (ed), Kommentar zum Einheitlichen UN-Kaufrecht, 3rd ed, Art. 7 CISG, para. 35)."
For further comments to the same effect, see John O. Honnold, "Uniform Law for International Sales under the 1980 United Nations Convention", 4th ed., Wolters Kluwer Law & Business (July 2009) [edited and updated by Harry M. Flechtner] § 372.3
8. Ulrich G. Schroeter, "The CISG's Final Provisions", in: Camilla B. Andersen / Ulrich G. Schroeter eds., Sharing International Commercial Law across National Boundaries: Festschrift for Albert H. Kritzer on the Occasion of his Eightieth Birthday, Wildy, Simmonds & Hill Publishing (2008) 429.
9. Pascal Hachem, Peter Schlechtriem & Ingeborg Schwenzer, in: Ingeborg Schwenzer, ed., Peter Schlechtriem & Ingeborg Schwenzer Commentary on the UN Convention on the International Sale of Goods CISG), Third (English) Edition, Oxford University Press (2010) 1199.