Inclusion of Ts&Cs
Swiss law requires that the Ts&Cs must be agreed on between the parties in order to have them validly included into a contract.
Such agreement can be express, e.g. in a framework agreement. While an implied agreement is not sufficient in consumer contracts, this should - according to the jurisprudence of the Swiss Federal Supreme Court – be adequate in B2B relations.
An express reference to the own Ts&Cs on offer and/or order documents is – even if not expressly accepted by the other party – sufficient (unless there is a Battle of Forms situation).
Whether a reference on a confirmation document is sufficient, is unclear under Swiss law. At least in situations where the recipient of the confirmation document, which newly contains a reference to the Ts&Cs, subsequently fulfils the contract, there are good arguments for supporting the position that such reference is sufficient. The situation is, however, less clear if the recipient of the confirmation document does not perform any contractual duties but only accepts the delivery by the other party.
A reference to the Ts&Cs on shipment documents or invoices is, however, generally not sufficient for a valid inclusion of Ts&Cs.
It is not necessary to include the Ts&Cs’ actual wording in the contract. However, the other party shall, prior to the conclusion of the contract, have the opportunity to take, in a reasonable manner, notice of the contents of the Ts&Cs. For fulfilling this requirement, it is not always necessary to physically handover the Ts&Cs to the other party. It is, for example, also sufficient if the contract is concluded by e-mail and the e-mail contains a reference/link to the website where the Ts&Cs can be downloaded or if the Ts&Cs are attached as a pdf-document to the corresponding e-mail. It is, however, unclear whether a reference to the website in ordinary written communication is also sufficient. And the latest jurisprudence of the Swiss Federal Supreme Court seems to indicate that it is even in B2B relations most likely not sufficient if the other party is only given the opportunity to ask for the Ts&Cs to be sent over (in consumer contracts, the mere offering to send over the Ts&Cs is never sufficient).
Finally, the Ts&Cs shall not be drafted in a language uncommon at the place where the contract is concluded if the other party is not familiar with such language.
The legal situation is similar to the national law, however:
There is a tendency that, also in B2B relations, the reference to the Ts&Cs in the main contract must always be an express one. At least, the requirements for an implied agreement seem to be higher than under Swiss law.
Furthermore, the mere reference to the website (containing the Ts&Cs) in ordinary written communication or the direction that the other party is given the opportunity to ask for the Ts&Cs to be sent over seem generally not to be sufficient for a valid incorporation of the Ts&Cs into the contract (whereas the corresponding situation under Swiss law is less clear in B2B relations).
Battle of Forms
Under Swiss law, the prevailing doctrine supports the Knock-Out Rule. Only a few legal commentators argue in favour of the Last-Shot Rule.
From a Swiss law perspective, under the CISG, the same situation applies as under national law.