There are loads of coin holders on Thingiverse, and for loads of different currencies - but not too many for UK coins. So here is my contribution. There's even a slot for folded bank notes if you're lucky enough to have some.

I've uploaded the sketchup file so you can adapt it if you want. Don't forget to print at 102% if you're using ABS otherwise the coins won't fit!

I've just uploaded a larger version which also has a £2 coin slot.

Just remember to print at 102% in ABS as the internal diameter dimensions have to be large enough to accept the coins.

The sketchup file is there too so you can add someone's name on the back to personalise it.

This version is a bit tight for the 50p's so I'd go bit larger and print at 103%-104% or go in to the sketchup file and make the hole a bit bigger.