Inclusion of Ts&Cs
Dutch law requires that the Ts&Cs must be agreed on in order to have them validly included.
The agreement can be express, e.g. in a framework agreement, but also implied. The implied inclusion requires a noticeable reference to one’s Ts&Cs. In particular, it is necessary to unambiguously name the Ts&Cs to which reference is made.
A reference to one’s Ts&Cs on offer documents and/or order documents is sufficient (unless there is a Battle of Forms situation).
Whether a reference on a confirmation document is sufficient, is somewhat unclear under Dutch law. The majority of case law and legal commentators seem to advocate that such reference is insufficient.
Ts&Cs must be declared applicable before or during the conclusion of the agreement to make sure Ts&Cs are applicable to the order. Therefore repeated reference on invoices or on shipment documents is generally not sufficient for a valid inclusion of Ts&Cs.
Moreover, Ts&Cs must be released to a customer before or during the conclusion of the agreement. If the Ts&Cs have been referred to, but have not been provided to the other party, the other party may nullify such conditions.
The requirement of making the Ts&Cs available does not apply to international agreements, i.e. agreements between a Dutch company and a non-Dutch supplier or customer
From a Dutch law perspective, under the CISG, the latest court decisions are in line with CISG-AC Opinion No. 13, Inclusion of Standard Terms under the CISG.
Battle of Forms
Under Dutch law, neither the Last-Shot nor the Knock-Out Rule applies. Instead, the „First-Shot Rule“ is applicable.
From a Dutch law perspective, under the CISG, the latest court decisions support the application of the Knock-Out Rule.