VI. Freedom of Form
In line with most modern contract laws, Art. 11 lays down the principle of freedom of form for the CISG:
A contract of sale need not be concluded in or evidenced by writing and is not subject to any other requirement as to form. It may be proved by any means, including witnesses.
1. Scope and Content
According to its wording Art. 11 applies to the formation of contracts. But it moreover sets the standard of form for all communications under the CISG as a general principle in terms of Art. 7(2). Freedom of form thus also applies to the modification of contracts under Art. 29 and to any notice made under the CISG. In contrast, Art. 11 does not apply to choice of forum or arbitration clauses contained in international sales contracts. The CISG was never intended to supersede the specific formal requirements for these clauses contained in domestic procedural laws.
The provision seeks to bar the application of all formal requirements of domestic laws regardless of their legal nature. This does encompass formal validity requirements such as direct writing or signature requirements or the requirement of consideration. Art. 11 sentence 2 clarifies that furthermore formal evidentiary requirements such as the Statute of Frauds or the parol evidence rule are superseded regardless of their domestic classification as part of procedural or substantive law.
Freedom of form was a very controversial issue during the drafting of the CISG. As a compromise, the possibility to limit freedom of form by making a reservation according to Art. 96 was implemented. This provision reads:
A Contracting State whose legislation requires contracts of sale to be concluded in or evidenced by writing may at any time make a declaration in accordance with article 12 that any provision of article 11, article 29, or Part II of this Convention, that allows a contract of sale or its modification or termination by agreement or any offer, acceptance, or other indication of intention to be made in any form other than in writing, does not apply where any party has his place of business in that State.
Accordingly, if a party has its place of business in a member state whose domestic law submits sales contracts to formal requirements and has made an Art. 96 reservation the CISG’s freedom of form does not apply. Art. 12 even makes this provision the sole mandatory provision of the CISG:
Any provision of article 11, article 29 or Part II of this Convention that allows a contract of sale or its modification or termination by agreement or any offer, acceptance or other indication of intention to be made in any form other than in writing does not apply where any party has his place of business ￼in a Contracting State which has made a declaration under article 96 of this Convention. The parties may not derogate from or vary the effect of this article.
Neither Art. 96 nor Art. 12, however, positively define what standard of form applies in case of the exclusion of the freedom of form principle under the CISG (disputed). Therefore, the applicable standard of form is determined by the forum’s international private law. Notably, if this results in the application of the law of a CISG member state that has not made a reservation under Art. 96 it is not the domestic standard of form that applies but Art. 11. While it seems contradictory on first glance that Art. 11 is first excluded and nevertheless applied in the end, this result is actually in line with the aims of the Art. 96 reservation. The reservation enables member states to preserve their domestic form requirements with regard to international sales contracts. On the other hand, it is not meant to extend the application of domestic form requirements. Consequently, in case of an Art. 96 reservation the domestic form requirements of the reservation state only apply if they would apply in case the member state had not ratified the CISG, i.e. if the forum’s international private law mandate their application. If the forum’s international private law find the law of a non-reservation member state applicable freedom of form under Art. 11 applies.
3. Party Autonomy
In accordance with Art. 6, the parties are of course free to agree on formal requirements for their contract or for their communications.
a. Contractual Form Requirements
Contractual form requirements have to be interpreted according to Art. 8 to determine their content (e.g. writing, signature etc.) and their purpose. With regard to the latter, particular regard is to be had to the question whether the formal requirement is meant to be a prerequisite of validity or merely to serve evidentiary purposes.
b. Definition of Writing
Art. 13 reads:
For the purposes of this Convention “writing” includes telegram and telex.
This provision determines the content of a writing requirement agreed by the parties. Despite listing specific forms of communication, this provision should be read in a more media-neutral way in order to give regard to modern day developments in communication. Decisive to be in “writing” is thus that the communication produces a record that can be permanently stored.