Excerpt from John O. Honnold, Uniform Law for International Sales under the 1980 United Nations Convention, 3rd ed. (1999), page 199 Reproduced with permission of the publisher, Kluwer Law International, The Hague.
§177 Under Article 15(2), an offer, even if it is irrevocable, may be withdrawn "if the withdrawal reaches the offeree before or at the same time as the offer." The present article applies this approach to the acceptance:
"An acceptance may be withdrawn if the withdrawal reaches the offeror before or at the same time as the acceptance would have become effective."
The time when acceptance becomes "effective", as specified in Article 18(2), is "the moment the indication of assent reaches the offeror".
The discussion of Article 15 (supra at §138) applies to Article 22. Indeed, these articles may constitute specific applications of a general principle that a party may withdraw or modify a communication by a second communication that overtakes the first. (See the Commentary to Article 7, supra at §96.) Schlechtriem, Com. (1998) 157–158.[page 199]
FOOTNOTES: Chapter on Article 22
1. This article is the same as Art. 20 of the 1978 Draft Convention and is similar to ULF 10.