Guide to the use of this commentary
The Secretariat Commentary is on the 1978 Draft of the CISG, not the Official Text, which re-numbered most of the articles of the 1978 Draft. The Secretariat Commentary on article 47 of the 1978 Draft is quoted below with the article references contained in this commentary conformed to the numerical sequence of the Official Text, e.g., article 47 [draft counterpart of CISG article 51].
To the extent it is relevant to the Official Text, the
Secretariat Commentary on the 1978 Draft is perhaps the
most authoritative source one can cite. It is the closest
counterpart to an Official Commentary on the CISG. A
match-up of this article of the 1978 Draft with the version
adopted for the Official Text is necessary to document the
relevancy of the Secretariat Commentary on this article. See
the match-up for this article for a validation of citations
to this Secretariat Commentary. This match-up indicates that article 47 of the 1978
Draft and CISG article 51 are substantively identical.
Text of Secretariat Commentary on article 47 of the 1978 Draft
[draft counterpart of CISG article 51] [Partial non-performance]
PRIOR UNIFORM LAW
ULIS, article 45.
1. Article 47 [draft counterpart of CISG article 51] states the buyer's remedies when the seller fails to perform only a part of his obligations.
Remedies in Respect of the Non-Conforming Part, Paragraph (1)
["Article 51(1) gives Buyer these options -- he may (i) require the Seller to deliver substitute goods (Art. 46(2)) or (ii) 'avoid the contract' (i.e., reject) with respect to the defective units (Art. 49(1)(a)) or (iii) accept the defective goods and reduce their price (Art. 50) or claim damages (Art. 74). Article 51(1) also assures Seller of the right to cure under Article 48 ... with respect to [the part which is missing or which does not conform]." John O. Honnold, 'Uniform Law for International Sales under the 1980 United Nations Convention" [Honnold Text], 2d ed., Kluwer Law International (1991), p. 400).]
2. Paragraph (1) provides that if the seller has failed to perform only a part of his obligations under the contract by delivering only a part of the goods or by delivering some goods which do not conform to the contract, the provisions of article 42 to 46 [draft counterpart of CISG articles 46 to 50] apply in respect of the quantity which is missing or which does not conform to the contract. In effect, this paragraph provides that the buyer can avoid a part of the contract under article 45 [draft counterpart of CISG article 49]. This rule was necessary because in some legal systems a party cannot avoid only a part of the contract. In those legal systems the conditions for determining whether the contract can be avoided at all must be determined by reference to the entire contract. However, under article 47(1) [draft counterpart of CISG article 51(1)] it is clear that under this Convention the buyer is able to avoid a part of the contract if the criteria for avoidance are met as to that part.
[See also Article 73 which is applicable to installment contracts. Where there has been a fundamental breach, Article 73 grants to the buyer (and, to the seller also) the right to avoid in whole or in part. In an installment sale, the buyer can choose between Article 51 and Article 73. Bennett reports: "Advantages of Article 73 are that it provides specifically for instalment deliveries and for avoidance of not only the instalment in respect of which a breach has occurred but of future and interdependent instalments. It should also be noted that there is no express requirement in Article 73(1) to act 'within a reasonable time' as there is for action [for other than non-delivery] under Article 51. On the other hand, under Article 73(1) a non-performance must constitute a fundamental breach with respect to the instalment in question, whereas Article 51 attracts the provision in Article 47 for the fixing of an additional period for the seller to perform his obligations and the related provision in Article 49(1)(b) for avoidance on the ground that delivery is not effected within that time, irrespective of whether this constitutes a fundamental breach of the relevant part of the contract. If, as could often be the case, the buyer fixes such an additional period for delivery of an instalment and the instalment then is not delivered within that additional time, he can avoid any question as to whether there has been a fundamental breach by acting under Article 51." H.T. Bennett, Bianca-Bonell Commentary, Milan: Giuffrè (1987), p. 536; see also Fritz Enderlein & Dietrich Maskow, "International Sales", Oceana (1992), p. 295.]
Remedies in Respect of the Entire Contract, Paragraph (2)
3. Paragraph (2) provides that the buyer may avoid the entire contract "only if the failure to make delivery completely or in conformity with the contract amounts to a fundamental breach of the contract:. Although this provisions reiterates the rule which would otherwise be applied under article 45(1)(a) [draft counterpart of CISG article 49(1)(a)], it is useful that it be made clear.
["One of the purposes of paragraph (2) of Article 51 is to make clear that paragraph (1) does not force the buyer to sort out the non-conforming goods for separate handling. The buyer may 'avoid (reject) as to the entire delivery if the breach as to part causes detriment that is so substantial as to constitute a fundamental breach' of the contract as a whole. The definition of 'fundamental breach' in Article 25 ... calls for close examination of the facts of the case in relation to the policies served by avoidance. One factor of special significance with respect to a partial avoidance is whether the nonconformity of some of the goods interferes with the use or salability of the remainder. ..." Honnold Text, 2d ed., p. 401.]
4. The use of the world "only" in article 47(2) [draft counterpart of CISG article 51(2)] also has the effect of negating the implication which might have been thought to flow from article 45(1)(b) [draft counterpart of CISG article 49(1)(b)] that the entire contract could be avoided on the grounds that the seller failed to deliver a part of the goods within the additional period of time fixed by the buyer in accordance with article 43 [draft counterpart of CISG article 47] even though such failure to deliver did not in itself amount to a fundamental breach of the entire contract (OFFICIAL RECORDS, pp. 43-44).