How portable are different UK bank notes across the UK?

In the past I was happy to accept Sterling (GBP) notes issued by any bank, because all bank notes were printed on special paper that could be tested with a cheap and readily available banknote pen. Very few forgers would use, or could obtain, the correct paper. So as long as the note appeared to say the right things, had embossed ink and passed the pen test, I would consider it to be genuine, and I could pay it into a bank (even if I could not spend it in a shop).

Now though, notes have been re-issued in the new plastic style. These are supposed to be harder to forge, but the catch is I am not well versed with the anti-forgery techniques used, and do not know what they are supposed to look like. The detector pen is no use. So I refuse all notes that are not issued by the Bank of England.

So speaking as a vendor in England, I will not now accept any notes issued by banks of Northern Ireland or Scotland. Moreover, I now prefer card payments to cash anyway.

If there is a 'trick' to it, pay by card. There are some vendors who still do not accept card payments, or who refuse small value card transactions, but the way things are going, they won't stay in business for long...

In theory, all these notes are mostly portable, although it is worth noting that only Bank of England notes are legal tender anywhere within the UK. However, settling a court-mandated debt is unlikely to figure in most visitors concerns, so that is largely irrelevant.

In practice, most staff taking the notes off you will only have experience with Bank of England notes and notes issued by local banks. They will often decline to take notes they are unfamiliar with simply because they do not know if what you are offering is a legitimate note, a fraudulent one, or simply an entirely fictional one from "The bank of dhinson919".

For a visitor travelling around the UK, this can be somewhat frustrating (although it is worth noting that in 2021, cashless payment is by far the norm, with more than 80% of transactions now being electronic). Some solutions you can attempt to employ:

• Request Bank of England notes before leaving the territory where other notes are issued
• Use automated devices - most "self checkouts" will accept all valid notes, but will give change in local notes (and coins that have no such problems)
• Attempt to exchange your national notes for Bank of England at any physical bank branch (note that some offer this service to customers only).

One other thing to consider is that, since covid, it is perfectly possible to not use bank notes at all. Practically everywhere will accept contactless payment. I live in the UK and do not carry cash at all now, have not used it for over a year.