I have been with my bank for over 30 years and have a good rapport with the staff behind the counter. IWhen I go in I always ask if they have any AA01, AA** prefixes on the £10 and £5 polymers. I always pick up notes in this way. The polymer collection of AA01s and AA prefixes has become quite substantial so I have to thank the tellers and cashiers for their kindness……do the same and you can pick up some good notes. If I was in Scotland I would be asking for aUNC £100 notes….after a few years they increase in value. So, it’s not always necessary to go to auctions when you have friendly bank staff.