"The Medway Handyman"
I've checked on the Royal Mint site and I can pay them £5 in 5p coins, £5
in 10p's, £10 in 20p's and £10 in 50p's - which they can't refuse to
accept.

Small minded, petty, mean & shallow it may be

No.,

It IS.

And silly to boot.

- but I'm going to do it anyway.

I'm wondering though, does it have to be bagged like the bank or can I
jumble the whole lot up & make them count it?

Is your time of so little value that you're prepared to stand over them
watching them do that?