But in my case I will give you the 'cash price' to make you say 'yes'. I still put it through the books though. Where is the collusion there? Until payment by cash is outlawed - then it is totally legal.
Or another scenario could be that you set up a computer system for your brother in law - and he (if he is a mechanic) fixes your car.
Do you 'bill' each other or fiddle the tax?
Yeah, i know what you mean, i often do 'contra-deals' like that.
I'm just quoting what i read really.