Art. 116 PILA from 2022

Art. 116 1. In general
1 Contracts are governed by the law chosen by the parties.
2 The choice of law must be express or result with certainty from the provisions of the contract or from the circumstances; apart from that, it is governed by the chosen law.
3 The choice of law may be made or changed at any time. If a choice of law is made after the conclusion of the contract, it has retroactive effect as of the time of conclusion of the contract. The rights of third parties are reserved.
Es besteht kein Anspruch auf Aktualität und Vollständigkeit/Richtigkeit.