French and UK coins/banknotes

I am travelling to the UK soon (Thursday) so if anyone is looking for any French coins or something I might be able to get them, I could bring them back to the UK and post from there (as cheaper).

If there is any French person (or anyone else really) who would like British coins/banknotes or Scottish banknotes (including the 4 new polymer £5 banknotes), I can bring them back with me on my return.

S'il y a quelqu'un qui a besoin de billets britanniques ou ecossaises, ou bien de pieces britannique, je peux les obtenir au Royaume-Uni quan je vais jeudi.