Holding 'customers' money

[MrC]

Punter A signs up to our service
Punter A directs Punter B, C, D, E etc to our site
Punter B, C, D, etc deposits money, knowing it will go to Punter A
After a while we give Punter A all the money deposited from Punters B, C, D etc

I tried to keep it simple and generic, but if more details are need I can flesh it out.

The question is, what are the implications to doing this? I am presuming (possibly wrongly) that taking in money will always be taxed in one way or another on the way to passing it out? Or do I just hold it and as long as I don't take any out, spend it or pay interest there are no implications? What about the interest it will incurr in my bank account during this time?

Sounds like a can of worms on the surface, hopefully you can shed some light!