The highest numbered £1 note recorded so far.EDIT: 08.09.15 Not any more! A new highest numbered note has turned up, see posts following.
Central Bank of Ireland, Lavery One Pound note 1976, highest number seen so far.
I found this in an envelope recently, put aside in the late 1990s, the highest number I'd seen then, and still the highest now.
The highest numbered £5 note.
Available data from the Central Bank of Ireland indicates that this is the highest-numbered £5 note.
Central Bank of Ireland 5 Pounds 1975 highest number.