The United Nations Convention on Contracts for the International Sale of Goods (CISG), sometimes known as the Vienna Convention, is a multilateral treaty that establishes a uniform framework for international commerce.United Nations Convention on Contracts for the International Sale of Goods, Vienna, 11 April 1980, S.Treaty Document Number 98-9 (1984), UN Document Number A/CONF 97/19, 1489 UNTS 3. The full text of the CISG is available in pdf format at https://uncitral.un.org/sites/uncitral.un.org/files/media-documents/uncitral/en/a-conf-97-19-ocred-eng.pdf at 14 February 2022.Not to be confused with other treaties signed in Vienna. As of September 2023, it has been ratified or acceded to by 97 countries, representing two-thirds of world trade.
The CISG facilitates international trade by removing legal barriers among state parties (known as "Contracting States") and providing uniform rules that govern most aspects of a commercial transaction, such as contract formation, the means of delivery, parties' obligations, and remedies for breach of contract.United States Department of Commerce, 'The U.N. Convention on Contracts for the International Sale of Goods' at 22 December 2007. Unless expressly excluded by the contract,Standard clauses in English and in German (opt-in/opt-out): See Verweyen, Foerster, Toufar Handbuch des Internationalen Warenkaufs UN-Kaufrecht (CISG) 2. Auflage, 2008 pg. 64 the convention is automatically incorporated into the domestic laws of Contracting States and applies directly to a transaction of goods between their nationals.This statement is only applicable for the US, the Czech Republic, and China, see Article 1,1B/95 Verweyen, Foerster, Toufar Handbuch des Internationalen Warenkaufs UN-Kaufrecht (CISG) 2. Auflage, 2008 pt. 21.2 pg 248
The CISG is rooted in two earlier international sales treaties first developed in 1930 by the International Institute for the Unification of Private Law (UNIDROIT). When neither convention garnered widespread global support, the United Nations Commission on International Trade Law (UNCITRAL) drew from the existing texts to develop the CISG in 1968. A draft document was submitted to the Conference on the International Sale of Goods held in Vienna, Austria in 1980. Following weeks of negotiation and modification, the CISG was unanimously approved and opened for ratification; it came into force on 1 January 1988 following ratification by 11 countries.Argentina, China, Egypt, France, Hungary, Italy, Lesotho, Syria, the United States, Yugoslavia, and Zambia.
The CISG has been described as one of the greatest achievements of UNCITRAL and the "most successful international document" in unified international sales law,Joseph Lookofsky, 'Loose Ends and Contorts in International Sales: Problems in the Harmonization of Private Law Rules' (1991) 39 American Journal of Comparative Law 403.Bruno Zeller, CISG and the Unification of International Trade Law (1st ed, 2007) 94. due to its parties representing "every geographical region, every stage of economic development and every major legal, social and economic system".John Felemegas, 'The United Nations Convention on Contracts for the International Sale of Goods: Article 7 and Uniform Interpretation (2000)' Pace Review of the Convention on Contracts for the International Sale of Goods (CISG) 115. Of the uniform law conventions, the CISG has been described as having "the greatest influence on the law of worldwide trans-border commerce", including among nonmembers.Peter Schlechtriem, 'Requirements of Application and Sphere of Applicability of the CISG' (2005) 36 Victoria University of Wellington Law Review 781. It is also the basis of the annual Willem C. Vis International Commercial Arbitration Moot, one of the largest and most prominent international moot court competitions in the world.
CISG art. 66 is a supplement to an inadequate Incoterms rule; CISG also coworks with Rome I and UCP 600 for standardization of the rules governing Letters of Credit to standardise transactions and benefit all parties and the maritime law about liability of the carrier.
Adoption
As of 1 September 2025, the following 97 states have ratified, acceded to, or succeeded to the convention:The status of signatories to the Convention is listed at https://treaties.un.org/Pages/ViewDetails.aspx?src=TREATY&mtdsg_no=X-10&chapter=10&clang=_en.
The convention has been signed, but not ratified, by Ghana (11 April 1980) and Venezuela (28 September 1981).
The former Yugoslavia had signed and ratified the Convention on 11 April 1980 and 27 March 1985, respectively. Bosnia and Herzegovina, Croatia, Slovenia and North Macedonia became parties by succession. Czechoslovakia had signed and ratified the Convention on 1 September 1981 and 5 March 1990, respectively. The Czech Republic and Slovakia became parties by succession.
Language, structure, and content The CISG is written using "plain language that refers to things and events for which there are words of common content".John Honnold, Uniform Law for International Sales under the 1980 United Nations Convention (3rd ed. 1999) 88. This was intended to allow national legal systems to be transcended through the use of a lingua franca that would be mutually intelligible among different cultural, legal, and linguistic groups.Jan Hellner, 'The UN Convention on International Sales of Goods – An Outsider's View' in Erik Jayme (ed) Ius Inter Nationes: Festschrift fur Stefan Riesenfeld (1983) 72, 76. and to avoid "words associated with specific domestic legal nuances". As is customary in UN conventions, all six official languages of the UN are equally authentic.Article 101.Arabic, Chinese, English, French, Russian, and Spanish / non-official translations of the CISG See: http://www.fr-lawfirm.de/links/pages/UN-Kaufrecht/Texte_Uebersetzungen/.
The CISG is divided into four parts:
Part I: Sphere of Application and General Provisions (Articles 1–13)
The CISG applies to contracts of the sale of goods between parties whose places of business are in different States, when the States are Contracting States (Article 1(1)(a)). Given the significant number of Contracting States, this is the usual path to the CISG's applicability.
The CISG also applies if the parties are situated in different countries (which need not be Contracting States) and the conflict of law rules lead to the application of the law of a Contracting State.Article 1 (b). For example, a contract between a Japanese trader and a Brazilian trader may contain a clause that arbitration will be in Sydney under Australian lawMore correctly, the law of New South Wales as mandated in Sale of Goods (Vienna Convention) Act 1986 (NSW). with the consequence that the CISG would apply. A number of States have declared they will not be bound by this condition.Specifically, China, Germany, Czech Republic, Saint Vincent and the Grenadines, Singapore, Slovakia, and the United States of America. See http://www.uncitral.org/uncitral/en/uncitral_texts/sale_goods/1980CISG_status.html at 22 December 2007.
The CISG is intended to apply to commercial goods and products only. With some limited exceptions, it does not apply to personal, family, or household goods, nor does it apply to auctions, ships, aircraft,Article 2. or intangiblesFrom Article 2 (d) and (f), intangibles such as stocks, shares, investment securities, negotiable instruments or money, and electricity. and services.Article 3- However, Sale of Goods contracts under the CISG may include services (e.g., transport, erection, supervision, training) up to 50% of the agreed contract price at the date of the signature of the contract (See Verweyen/Foerster/Toufar Handbuch des Internationalen Warenkaufs UN-Kaufrechts (CISG) 2. Auflage, 2008 2.1.1 p. 46) The position of computer software is 'controversial' and will depend upon various conditions and situations.Peter Schlechtriem, 'Requirements of Application and Sphere of Applicability of the CISG' (2005) 36 Victoria University of Wellington Law Review 781.Frank Diedrich, 'Maintaining Uniformity in International Uniform Law Via Autonomous Interpretation: Software Contracts and the CISG' (1996) 8 Pace International Law Review 303, 321, 322.
Importantly, parties to a contract may exclude or vary the application of the CISG.Articles 6, 12.
Interpretation of the CISG must consider the "international character" of the convention, the need for uniform application, and the need for good faith in international trade.Article 7.
A key point of controversy is whether or not a contract requires a written memorial to be binding. The CISG allows for a sale to be oral or unsigned,Article 11. but in some countries, contracts are not valid unless written. In many nations, however, oral contracts are accepted, and those States had no objection to signing, so States with a strict written requirement exercised their ability to exclude those articles relating to oral contracts, enabling them to sign as well.Specifically, Argentina, Belarus, Chile, China, Hungary, Latvia, Lithuania, Paraguay, Russian Federation, and Ukraine are not bound by Article 11.
The CISG, by its own definition, does not govern all aspects of sales contracts subject to its application.Article 4, 5 The matters listed in its Article 4 must be filled in by the applicable national law under due consideration of the conflict of law rules applicable at the place of jurisdiction.In the toolbox (CD-Rom, which is attached to the Verweyen, Foerster, Toufar Handbuch des Internationalen Warenkaufs UN-Kaufrecht (CISG) 2. Auflage, 2008, the parties can easily identify the gaps and how they will be filled under the assumption of Swiss or German applicable law. This toolbox also comprises a software to determine the application of the CISG Gaps referring to matters that are governed by the CISG but not expressly settled therein (a gap praeter legem), however, are to be preferably filled in accordance with "the principles on which [the CISG] is based," and only in the absence of those should national law be applied.Article 7 (2)
Part II: Formation of the Contract (Articles 14–24)
An offer to contract must be addressed to a person, be sufficiently definite – that is, describe the goods, quantity, and price – and indicate an intention for the offeror to be bound on acceptance.Article 14. The CISG does not appear to recognise common law unilateral contractsSee, for example, Carlill v. Carbolic Smoke Ball Company (1892) 2 QB 484. but, subject to clear indication by the offeror, treats any proposal not addressed to a specific person as only an invitation to make an offer.Article 14 (2). Further, where there is no explicit price or procedure to implicitly determine price, then the parties are assumed to have agreed upon a price based upon that 'generally charged at the time of the conclusion of the contract for such goods sold under comparable circumstances'.Article 55.
Generally, an offer may be revoked provided the withdrawal reaches the offeree before or at the same time as the offer, or before the offeree has sent an acceptance.Articles 15, 16 (1). Some offers may not be revoked; for example when the offeree reasonably relied upon the offer as being irrevocable.Article 16 (2). The CISG requires a positive act to indicate acceptance; silence or inactivity are not an acceptance.Article 18.
The CISG attempts to resolve the common situation where an offeree's reply to an offer accepts the original offer, but attempts to change the conditions. The CISG says that any change to the original conditions is a rejection of the offer—it is a counter-offer—unless the modified terms do not materially alter the terms of the offer. Changes to price, payment, quality, quantity, delivery, liability of the parties, and arbitration conditions may all materially alter the terms of the offer.Article 19.
Part III: Sale of Goods (Articles 25–88)