Last week LBG issued a £750m 3 year FRN at 43 over SONIA, the first UK bank to issue over SONIA.  The FT reports it was well received, almost 2x oversubscribed.  It uses backwards-looking SONIA with daily compounding and a five “London Banking Day” period between the end of the “observation period” and the interest payment date (as did the EIB in June).  The publicly-available pricing supplement contains all the relevant drafting.