Co-tenancy: flat share or sub-let?

Imagine living in Zurich and having a rental agreement for a centrally located, affordable flat in an old building. The university is within walking distance.

A sub-tenant from abroad lives with you for a year. This involves very little bureaucracy and there are never any issues. Unfortunately, the flat share only lasts for this limited period, after which your sub-tenant returns home. Suddenly, you receive a big heating bill for the final weeks of her sub-tenancy. You didn’t bother with any formalities when sub-letting. The rent was paid in cash, there was no mention of bills and you didn’t ask for a deposit. And who will repaint the wall that your flatmate painted purple?

If you live with other people, sooner or later, you’ll need to clarify important tenancy law issues in a contract. Informal sub-lets or co-tenancies can be verbally agreed.

Co-tenancy: when everyone is included in the rental agreement

In this model, everyone who lives in the property jointly signs the rental agreement. Everyone is equally liable and has identical rights and obligations. This version is recommended for clear living arrangements that are likely to last a long time. For example, for flatmates who are planning to live together for an extended period.

The co-tenancy model is also ideal for couples cohabiting without marriage or those in a civil partnership. If you are a co-tenant in a flat share, you must take care of various formalities. The deposit is registered to a specific, named person, for example, and must be changed if this person then moves out. New contracts must also be drawn up (and possibly negotiated) every time someone moves out.

Co-tenants must always deal with the property owner jointly. If one tenant wants to move out, all the others must agree to this. Otherwise, that person will continue to be liable even after they have moved out.

Signing the rental agreement jointly or individually?

When a couple rent a flat together, they often wonder whether it is best for both or just one of them to sign the rental agreement.

For landlords, it is better if both of them sign. This allows them to demand rent from both people and gives them more security. For unmarried couples, it’s a bit more complicated. If the relationship breaks down, the tenancy can only be terminated if both of them sign the termination notice. We therefore recommend that only one person signs the rental agreement. This makes it clear from the outset who will remain in the flat (or give notice) should they separate. In the case of married (or formally cohabiting) couples, both of them must give notice, even if only one of them has signed the rental agreement.

Sub-letting is an alternative to co-tenancy. More details are available in our guide.