LIBOR will be replaced by SONIA from the beginning of 2022. With SONIA rates typically lower than LIBOR, banks will seek to make up the difference by application of a Credit Adjustment Spread (CAS), likely to be calculated by reference to the median difference between LIBOR and SONIA over the previous five-year period. This article considers the extent to which banks will be required to disclose the existence of the CAS and its method of calculation to customers in the light of previous findings by the court of the lack of an obligation on banks to disclose the Credit Line Utilisation (CLU) to customers.