Are contractual penalty clauses enforceable in Switzerland?

Why Swiss law is comfortable with penalties

Some legal systems treat penalty clauses with suspicion. Swiss law accepts them as an ordinary tool of contract design: the Code of Obligations expressly allows the parties to agree that a breach, whether late delivery, a breach of confidentiality or a violation of a non-compete, triggers payment of a fixed amount (Art. 160 CO).

The great practical advantage is evidentiary. The creditor does not have to prove that it suffered damage, or how much (Art. 161 CO). Where loss is real but hard to quantify, which describes most confidentiality and non-compete breaches, that shifts the balance of a dispute considerably.

A penalty clause also works before any dispute. A counterparty that knows a concrete number is attached to a breach behaves differently from one facing an abstract threat of "damages to be proven".

The judge's scissors

The counterweight is mandatory. Under Art. 163 CO, Swiss courts must reduce penalties they consider excessive, and the parties cannot contract out of that review. Whether a penalty is excessive is judged in the individual case: the seriousness of the breach and of the breaching party's fault, the creditor's interest in performance, the parties' economic circumstances, and the relationship between the penalty and any conceivable harm.

Two practical consequences follow. An absurdly high number does not give you more protection; it gives the other side an argument and invites the court to rewrite your clause. And reduction is not elimination. Even a reduced penalty typically leaves the creditor better off than proving damages from scratch. The clause rarely becomes worthless. It becomes smaller.

Note also that paying up does not close the question. In BGE 133 III 43 the Federal Supreme Court dealt with the reduction of a penalty that had already been performed.

Drafting points that decide enforcement

Most penalty disputes are lost on drafting rather than doctrine. The clauses that hold up share a few features:

• A precisely defined trigger. "Any breach of this agreement" invites argument; "disclosure of information designated confidential under clause X" does not. BGE 135 III 433 is the reference point on what the penalty may consist of and how definite the secured duty has to be.
• A stated relationship to damages: whether the penalty is owed in addition to performance or instead of it, and whether the creditor may claim damages exceeding the penalty. The law has default answers, but the defaults may not be what you want.
• An amount you can justify. Scale the figure to the interest actually protected, or use a graduated structure, per breach or per week of delay and with a cap, rather than one dramatic number.
• Clarity on fault: whether the penalty is owed regardless of fault or only for negligent or intentional breach. In employment relationships the room is narrower still, since a penalty has to sit alongside the mandatory rules on employee liability (BGE 144 III 327).

Whether a specific clause would survive review, and at what amount, depends on the contract and the facts around the breach. Before invoking or resisting a penalty, it is worth discussing your situation with a lawyer.