You are allowed to sublet your apartment if you get permission from us.

If you have adequate reasons to do so (medical or study-related, for instance), you may sublet your apartment. Subletting agreements must be approved by SGS and signed at the housing office. You must have been an SGS tenant for 6 months to sublet your apartment.
You will still be responsible for the apartment, and if the person you are subletting to damages anything or fails to pay the rent, you will be held accountable.

Application for subletting (PDF).

If you sublet your apartment without our approval, you run the risk of losing your rental agreement. If the lease holder and the resident are in the queue for an apartment they will both lose their time in the queue and will also be expelled for 3 months before they can submit a new application.