According to the information I found, it is generally the case that the professional contribution is owed to the tripartite national commission for the entire year (coiffuresuisse.ch). However, since your client intends to cease operations by the end of February, it can be argued that the contribution should be calculated proportionally to the months in which the company is actually active. This would correspond to a reduction to two months. It is advisable to contact Coiffeur Suisse or the tripartite national commission directly to discuss an amicable solution. There may be specific regulations or leniency provisions for cases such as the cessation of business within a year. A written inquiry or a request to reduce the professional contributions, outlining the circumstances, would be reasonable in this case. In this way, it is ensured that the reduction is examined and approved if applicable.