No need but if you want to start a new thread fine.
If I hand you cash, then you have lawful money - the redemption or not was up to me in getting that cash. Now if I make you sign any kind of receipt or even an agreement (work contract beforehand) that is when you would make your Demand above your signature.
That is pretty simple but I think a couple pages in a new thread might be fun. The people writing here are great!