You can’t talk about UK money without the slang. A quid is a pound. “That’ll be five quid.” Not “five pounds.” Quid. It’s not pluralized, so “ten quid” sounds like one unit of liquid cash. A nickel? No, that’s American. Here, a fiver is a £5 note, and a tenner is a £10 note. Say them with confidence.
Also, a pony is £25. A monkey is £500. Don’t ask why—it’s a mystery wrapped in a British beef pie. And if someone offers you a score? That’s £20. Yes, like the opening of ‘2001: A Space Odyssey’—but with better spending opportunities.