I popped into Lidl at lunch time to do some shopping and realised that I needed to top up my phone and didn't have much money, so to save myself 2 minutes stopping at the cash machine I took cash-back, which is something I have never done before.
The next stop was a little corner newsagents where I asked for a ten pound top up. She took the twenty note which I had just been given by Lidl and put one of these special pens on it, only to find that it was a forgery. Very embarrassing.
Now, in a situation like that the woman in the shop is supposed to confiscate it and give it to the police (which would mean me losing £20), but because she knows me, and trusts me, she let me keep it so that I could take it back to Lidl.
I went to the till (and assistant) from where I'd got the money. Fortunately he remembered me and remembered that he had given me cash-back of £20. He had to call the manager, of course and she asked some questions. The problem was that although the guy knew he had given me a £20 note, no one could prove that it was THAT £20 note.
In the end, again because I am a regular customer and have been since the shop opened, they took my word, although clearly they had no obligation to.
So twice this morning, I was in a situation where if the shops had stuck to the rules I would have been £20 short. They would have been perfectly entitled to do that, but they didn't.
So to the woman in the newsagent shop and to the manager of Lidl I say thank you for your trust. To Lidl I'd add that it might be worthwhile investing ion some of these pens for your tills.
Of course you can't avoid accepting change if you are paying in cash for something, but at least it is unlikely that you are going to lose more than a tenner (unless you are one of these people that pays for things with £50 or £100 notes.) You can however avoid cash-back and I'd advise you to do so unless it is impossible to get to a bank, or the shop giving the cash out tried the marker pen on them in your site.
It might be useful for you to know if you live in the area around Dundee that it was a Royal Bank note and that, when I studied it, it did seem a bit too lilac... but hey, hindsight has 20 - 20 vision.
If you have any, check them out.