Can my Roommate Cancel the rental agreement?

- A rental contract signed by two people can ONLY be terminated by both of them together. If you do not agree to terminate, both of you continue to rent the apartment (i.e. have to pay the rent and have the right to stay there).
- If the contract is terminated, the landlord is free to decide whom next to rent the apartment out to. It could be you, your (ex-)friend, somebody else or no-one.
- For the termination period, please check your contract. It is a minimum of 3 months by law, or more if you stayed there long.

The best course of action is to find a mutually agreeable solution with all involved, landlord, (ex-)friend and you!

I think Beppi has covered the legal viewpoint. From a practical standpoint I would wonder what the intention of this friend is? Do they want to take over the apartment for themselves or to move out and be out of the contract? If they want out then it would not seem to be a problem for you to just continue on as a sole renter. Or is there a specific reason the landlord wouldn’t want you out? As long as the rent gets paid then it is a pain for them to try to force someone out and doesn’t really offer any benefit. If the friend wants the apartment then it is basically between you and them and resolving the conflict might get difficult as they have the closer relationship to the landlord. I’m not sure how this is legally resolved. Normally, one person is the main renter and others, even with a contract, are designated sub-renters rather than co-renters. When things go well, the difference is irrelevant but in such a situation it could be critical.