In its ruling of 19 January 2021, the Higher Court of the Canton of Zurich dealt with the question under which circumstances the mortgage interest of a Libor mortgage can be reclaimed.

The question is relevant for Libor mortgages from the beginning of 2015, since which time the Libor interest rate in the Swiss franc has had a negative value.

Specifically, the question is whether the formula "Libor + margin = interest rate" applies between the bank and the debtor or whether the parties have agreed on a zero interest rate floor. In this case, the formula is "Libor, at least zero + margin = interest rate" (so-called zero interest floor). If there is no zero interest floor, a negative libor interest rate results in no or lower mortgage interest (e.g.: -0.75% + 0.80% = 0.05%).

The Zurich Supreme Court did not decide the case, but referred it back to the lower court. In this respect, the legal situation is not yet definitive.

The following scheme is intended to provide an initial rough assessment grid.