When someone starts working in Switzerland and the contract mentions a "bonus" or an "end-of-year bonus", many assume that it is something similar to the 13th salary. Signed, agreed, guaranteed. But it doesn't necessarily work like that.
The 13th salary is part of the salary. If it is in the applicable contract or collective agreement, the employer is obligated to pay it without exception. If you leave work in the middle of the year, you are entitled to the proportional part according to the months worked. There is no room for manoeuvre for the employer.
Gratification is something else. It is a payment that the employer decides according to criteria that he can set himself: company results, individual performance, or simply that the year has gone well. If the contract specifies that the amount is “discretionary” or depends on the benefit of the company, there is no obligation to pay on the same terms. What Swiss jurisprudence does recognize is that, if that bonus has been paid three years in a row unconditionally, it begins to be considered an acquired right. Up to that point, there is little to claim.
The specific problem: quite a few people in Switzerland sign contracts where what looks like a 13th salary is actually a discretionary bonus. In December comes the surprise. By then, sometimes, it's already too late to do anything about it.