Im getting conflicting googles, i think they reduced it to 75K last year because the GBP was getting stronger. Therefore you would think they will increase it to 100K now the GBP is crashing. Only way to increase is to open a joint account with a partner if you have one. Then you get double protection.
There was some Lloyd's of london extra insurance but it was something like 30million across all customers, but now IB have something like 30billlion in accounts it seems irrelevant and IB didnt want to increase it as customers could private protection from lloyds if they want it.