Neumann, Thomas, The Duty to Cooperate in International Sales - The Scope and Role of Article 80 CISG (2012), p. 110 et seq.


5.1.1 Positively Phrased Duties

A positively phrased principle is one that requires a party to engage in a certain conduct and in this regard article 80 expresses a common duty to cooperate with the other party.488

The principle of cooperation between the parties exists in the Convention489 and is expressed in many provisions. At least three groups of provisions require or presuppose certain cooperation, recognising that a sales transac­tion is a series of interrelated steps by each party.490

First, rules of communication of information in the interest of the other party are found in articles 19(2), 21(2), 26, 39(I), 48(2), 65, 68, 71(3), 72(2), 79(4) and 88(1).491 An example could be that article 21(2), which requires an addressee to notify the addressor when he realises that the otherwise late acceptance would have been received in due time. If he does not, the addressee is bound by the acceptance even though it may technically be late. This requirement of notification is in the other party's interest and imposes a duty for the addressee to cooperate.

Second, rules regarding the preservation of goods in articles 85-88 impose on a party a duty to cooperate by acting in the interest od te other party.492 111 An example could be article 86(1) requiring the buyer to preserve goods that he has received though he may wish to reject them. He may not, so to speak, let the delivered horse run away.

Third, there are rules requiring steps in order to enable the other party's performance, i.e. articles 54 and 60(a).493 These provisions again recognise that a sales transaction presupposes a series of interrelated steps to be taken by each party.494

An example of a step required to enable the other party's performance could be the naming of a particular place under FOB INCORTERMS.495 Such a situation is seen in the archetype case Propane Case.496  The case addressed that the buyer was supposed to nominate a ship since the parties had agreed to FOB delivery terms. However, the seller omitted to name the place of loading as agreed and consequently the buyer could not open a L/C, nor nominate a ship for the seller to load to the goods into. The adjudicator stated that by virtue of article 80 CISG the seller could not rely on the buyer's non-performance to avoid the contract since it was the seller himself who caused the buyer not to issue the L/C.497

Another case illustrates the duty to cooperate and that attempts to do so must be real. In Steel Channels Case498  the goods were detained by customs under the suspicion of smuggling. This caused the buyer to claim damages and the contract avoided due to seller's fundamental failure to deliver. The court found that the seller had delivered the goods correctly and that it was112 for the buyer to deal with customs. The buyer's claim of damages and avoid­ance were therefore rejected.

However, the seller knew that customs had questioned the goods twice be­fore and in the case at hand the seller made it difficult to solve the problems with customs since it forwarded to the buyer irrelevant documents. The tribunal therefore decided that the purchase price should be lowered by 30%, thus placing the burden between buyer and seller in a 70/30 ratio. A similar fraction was used regarding the arbitration fee and inspection costs.

The duty to cooperate is well recognized in international trade. Both case law applying general principles of law499  and international instruments have adopted rules regarding the duty to cooperate,500 for example UPICC 2010 Article 5.1.3501 (Co-operation between the parties);

'Each party shall cooperate with the other party when such co-operation may reasonably be expected for the performance of that party's obligations.'

Also TLP has adopted a principle addressing the duty to cooperate in No.IV.6.9(b) [Duty to Notify/To Coopcrate];

'(b) Each party is under a good faith obligation to cooperate with the other party when such cooperation can reasonably be expected for the performance of that party's obligations.'

An underlying principle requiring cooperation between the parties can thus be extrapolated from the CISG, is expressed also in article 80 and is possible to confirm in international soft law.113 Thus, though the Convention does not contain a provision expressly stating a duty to cooperate as it is done in UPICC, TLP, PECL, DCFR and ACQUIS Principles, it is underlying the Convention and article 80.

5.1.2 Negativly Phrased Duties

[...]114 lt is one thing to say that certain principles have been read into article 80. lt is another to say whether these principles are underlying the Convention. lt has been stated in Rolled Metal Sheets509  that the prohibition of venire contra factum proprium is a principle underlying the CISG.510

Further, the principle and the protection of the other party's reliance is commonly said to be expressed in articles 16(2), 29(2) and 80.511  However, a number of other articles have been mentioned in addition to those, for example articles 2, 7, 8(3), 9(2), 14(2), 18(2), 19(2), 21(2), 25, 33, 35(2)(b), 39(2), 41, 42(2)(b),46(1), 47(2), 48(2), 49(2), 62, 63(2), 64(2), 66.512

An example of venire contra factum proprium expressed in the CISG is article 16(2)(b). The provision establishes that an offer can not be revoked as it normally could be, if the offeree reasonably relied on the offer being irrevocable.The underlying principle was applied in Rolled Metal Sheets513 where the parties had agreed that notice of non-conformity should happen in writing
115 immediately after the delivery of the goods. The buyer sent a notice of non­ conformity six months after delivery, which according to the contract was too late. However, the adjudicator found that the seller's conduct led to the seller being estopped from raising the defence. After having received the late notice the seller did not object, but rather entered into negotiations and enquired about the status of the complaints from the buyer's buyer with the purpose of finding a solution.

Considering the many articles expressing the principle it is well-founded to claim that it underlies the Convention.514  The interpretation is confirmed with the principle of venire contra factum proprium or the prohibition of in­consistent conduct, being applied in practice as general principles of law.515  Further, it has been adopted in international restatements516  and may then act as interpretation aids for particular provisions in the CISG.517  See for example; 

UPICC 1.8 [Inconsistent behaviour];

'A party cannot act inconsistently with an understanding it has caused the other party to have and upon which that other party reasonably has acted in reliance to its detriment.'

116 TLP No. I.1.2 [Prohibition of inconsistent behaviour];  

'(a) A party cannot set itself in contradiction to its previous conduct vis­-à-vis another party if that latter party has acted in reasonable reliance on such conduct ("venire contra factum proprium"; "l'interdiction de se contredire au détriment d'autrui").
(b) Violation of this Principle may result in the loss, suspension, or modification of rights otherwise available to the party violating this Principle or to the creation of rights otherwise not available to the aggrieved party.'

The principles of venire contra factum proprium, duty not to abuse rights and not to derive a benefit from own wrong is underlying the Convention and is expressed in article 80.


5.2 A General Duty of Good Faith and Fair Dealing


Scholars and to some extent case law have confirmed that article 80 springs from good faith.521  However, it is controversial whether a general duty for the parties to act in good faith has been adopted in the Convention.117 Considering the controversy and the fact that article 80 rests on a general duty of good faith, it is of interest to clarify whether the attitude towards good faith is significant to the application of article 80. lf both trading par­ties are from jurisdiction that have a restricted view on good faith it may bee asked whether this in turn could restrict the use of article 80.

Furthermore, if the trading parties are from jurisdictions with a broad view on good faith, it is of interest whether it then is possible to define the content of the concept and let the concept of good faith inform the application of article 80.

Before elaborating the issues of good faith in relation to article 80 it is point­ed out that several different roles of good faith within the CISG exist.522  The first is, as a criterion for interpreting the Convention text. The requirement precludes absurd interpretations by requiring consideration of context, ob­ject and purpose.523  This is dealt with supra section 2.2.3, p. 27 et seq.
The second is, as a general principle underlying the Convention. Though it is not directly mentioncd in article 7(2), good faith has been said to be a principle underlying the CISG,524  thus making it a principle that can be used for gap-filing.525  If good faith is to be a workable underlying principle it must be possible to give it some specific content from which solutions can be derived. This is dealt with infra section 5.3, p. 133 et seq.

The third role is, as a general requirement imposed on the parties. This could follow from article 7(I) CISG in which good faith is mentioned. lt is of interest whether a possible concept of good faith would return similar results as article 80 or if a different approach is called for.


488 Flechtner/Honnold, Uniform Law, 2009, pp. 646-648.
489 Enderlein/Maskow, lnternational Sales Law, 1992, pp. 336-337, p. 351 and Magnus, General Principles, 1995, (5)(b)(11).
490 Flechtner/Honnold, Uniform Law, 2009, pp. 114-145, p. 424, pp. 428-430.
491 Flechtner/Honnold, Uniform Law, 2009, pp.144-145, p. 424, pp. 428-430. Regard­ing 79(4), see also Schwenzer, Commentary on CISG, 2010, article 79, para. 43, p. 1081.
492 Enderlein/Maskow, lnternational Sales Law, 1992, p. 351.
493 Flechtner/Honnold, Uniform Law, 2009, pp. 464-465 and pp. 487-488 and Bonell in Bianca/Bonell, Commentary, 1987, p. 81.
494 Flechtner/Honnold, Uniform Law, 2009, pp. 487-488.
495 Flechtner/Honnold, Uniform Law, 2009, pp. 487-489.
496 Oberster Gerichtshof [Supreme Court], Austria, Propane Case, 6 February 1996.
497 See also Bundesgerichtshof [Federal Supreme Court], Gerrnany, Machinery Case, 31 October 2001 confirming a duty to cooperate in CISG, but rejecting that it impose on a buyer a duty to inquire about standard terms.
498 China International Economic & Trade Arbitration Commission [CIETAC], China, Steel Channels Case, 18 November 1996. Notice that the tribunal wrongly considers Portugal a CISG state. See also China lnternational Economic & Trade Arbitration Commission [CIETAC], China, Hot-rolled Coils Case, 15 December 1997 regarding a typo in shipping documents regarding the vessels name and Landgericht Kassel [District Court], Germany, Wooden Poles Case, 21 September 1995 where the seller made unreasonable demands.
499 International Court of Arbitration, International Chamber of Commerce, Paris, France, Bleached Pizza Paper, 3 October 2003, No. 12111, International Chamber of Commerce. International Court of Arbitration, Geneva, Switzerland, Andersen Consulting Business Unit Member Firms vs. Arthur Andersen Business Unit Mem­ber Firms and Andersen Worldwide Societe Cooperative, 28 July 2000, No. 9797, Ad Hoc Arbitration, San José, Costa Rica, 30 April 2001 and Camera Arbitrale Nazionale ed lnternazionale di Milano [Chamber of Arbitration of Milan], ltaly, Steel Wire Case, 28 September 2001.
500 See for example TLP IV.6.9 [Duty to Notify/To Cooperate], PECL Article 1:202 [Duty to co-operate], ACQUIS Principles 7:104 [Duty to co-operate], DCFR III.1:I04 [Co-operation].
501 ln UPICC 1994 the article is numbered 5.1.3.
509 Internationales Schiedsgericht der Bundeskammer der gewerblichen Wirtschaft [Arbitration], Austria, Rolled Metal Sheets, 15 june 1994.
510 Compare, Arrondissementsrechtbank Amsterdam [District Court], Netherlands, Tuzzi Trend Tex Fashion v. Keijer-Somers, 5 October 1994, finding estoppel to be outside the Convention.
511 Kee and Opie, Principle of Remediation , 2008, p. 232, p. 241, Enderlein/Maskow, International Sales Law, 1992, p. 67, p. 210, p. 335, Mather, Henry, Firm Offers Un­der The UCC and the CISG, Dickson Law Review, 2000, 31-56, p. 48, Viscasillas, Maria del Pilar Perales, Modification And Termination of The Contract, Journal of Law and Commerce, 2005-2006, 167-179, p. 176. Magnus, General Principles, 1995. (5)(b)(4), Flechtner/Honnold, Uniform Law, 2009, pp. 142-145, pp. 422-423 and Lookofsky, Understanding CISG, 2008, p. 38.
512 Kee and Opie, Principle of Remediation, 2008, p. 232, fn. 36, Enderlein/ Maskow, lnternational Sales Law, 1992, p.67, p. 335, Flechtner/Honnold, Uniform Law, 2009, pp. 142-145, pp. 422-423 and Magnus, General Principles, 1995,(5)(b)(4).
513 Internationales Schiedsgericht der Bundeskammer der gewerblichen Wirtschaft [Arbitriation], Austria, Rolled Metal Sheets,15 June 1994.
514 Bazinas, Spiros V., Uniformity in The Interpretation and The Application of The CISG: The Role of CLOUT and The Digest, Collation of Papers at UNCITRAL SIAC Conference 22-23 September 2005, p. 25, Kee and Opie, Principle of Remediation, 2008,pp. 244-246 and Enderiein/Maskow, International Sales Law, 1992, p. 210.
515 International Chamber of Commerce, Geneva, Switzerland, 14 January 1970, No. 1512, lran-US Claims Tribunal, Abrahim Rahman Golshani v. The Government of The lslamic Republic of Iran, 2 March 1993, No. 812 and Court of Arbitration of Sport, The Gibraltar Football Association (GFA)/Union des Associations Europeénnes de Football (UEFA), 7 October 2003, CAS 2002/O/410.
516 See TLP No. I.1.2 [Prohibition of inconsistent behaviour], No. I.1.3 [Forteiture of rights], No. I.1.4 [Abuse of rights], UPICC Article 1.8 [lnconsistent behaviour], PECL Articles 2:105(4), 2:106(2), 202(3)(c), DCFR II.4:202(3)(c).
517 For the use of UPICC article 2.4(2)(b) and PECL article 2:202(3)(c) in relation to CISG article 16(2)(b), see Vincze ln Felemegas, An Int'l Approach, 2007, p. 91 and Akseli in Felemegas, An Int'l Approach, 2007, p. 307. For the use of UPICC article 2.18 in regard to article 29(2) CISG see Eiselen in Felemegas, An Int'l Approach, 2007, p. 166, who is more reserved regarding the use of PECL in this regard, ac­cording to Eiselen in Felemegas, An lnt'l Approach, 2007, pp. 342-345.
521 Enderlein/Maskow, International Sales Law, 1992, p. 335, Schäfer in Felemegas, An Int'l Approach, 2007, p. 246, Herber and Czerwenka, Internationales Kaufrecht, 1991, article 80. para. 2, p. 359, Magnus in Honsell, Heinrich und Karollus, M., Kommentar zum UN-kaufrecht: Übereinkommen der Vereinten Nationen über Verträge über der Internationalen Warenkauf­ (CISG), Springer, Berlin, l997,[Honsell Karollus, UN-Kaufrecht, 1997] article 80, para.s 1-2, pp. 994-995, Schwenzer in Schwenzer, Commentary on CISG, 2010, article 80, para. 1, p.1088, Audit, La Vente, 1990, p. 179, Viscasillas, Maria del Pilar Perales, El Contrato De Compraventa International De Mercancias (Convención De Viena De 1980), Pace Law School, New York, USA, 2001, [Viscasillas, El Contrato, 2001], 180. Exemption, Oberlandesgericht München [Appeilate Court], Germany Automobiles Case, 8 February 1995.
522 Keily, Troy, Good Faith and The Vienna Convention on Contracts for The lnternational Sale of Goods (CISG), Vindobona Journal of lnternational Commercial Law and Arbltration, lssue 1, 1999, [Keily, Good Faith and CISG,1999] pp. 22-23.
523 Villiger, Commentary on VCLT, 2009, article 31, para. 8, p. 426.
524 Enderlein/Maskow, International Sales Law, 1992, p. 56 and Bianca/ Bonell, Com­mentary, 1987, pp. 80 and 85.
525 Schlechtrlem in Schlechtriem/Schwenzer, Commentary on CISG, 2005, article 7, para. 7.

Referring Principles
Trans-Lex Principle: I.1.1 - Good faith and fair dealing in international trade
Trans-Lex Principle: I.1.2 - Prohibition of inconsistent behavior
Trans-Lex Principle: IV.6.9 - Duty to notify / to cooperate
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