They are difficult to spend in Scotland where you might think they would be used to a variety of notes. I remember the story a professor at the University of Ulster told me - he was in Glasgow and offered to pay a bill with a £10 Bank of Ireland note, but they wouldn't accept it. He found a Bank of England note in his wallet. In turn he refused a £5 Bank of Scotland note as part of his change explaining that, 'You wouldn't take one of mine so why should I take one of yours?'