Just a very small clarification here to avoid confusion, the "Bank of England" money is actually accepted everywhere in the UK. What ajamieson is referring to about difficulties with money outside the "home" area is the localised Scottish, Northern Irish etc money.

fierce_kali, you can indeed always request Bank of England notes in a Scottish or N. Irish bank and will be given them. I believe there is some legislation for this. It just means you have to go for counter service instead of use an ATM.

There are of course all sorts of sundry problems with all this. One is that the buffet attendant on the train from Edinburgh to London may only have Scottish notes left for change in the latter part of the journey, which comes as a surprise to Yorkshire miners travelling from Doncaster to London who go along for a beer, and leads to some interesting exchanges of opinion ! Another is that the local notes are not a country standard but are issued by each individual bank to their own design, which at a small corner store in London can lead to them accepting Bank of Scotland money but rejecting Clydesdale Bank ones.