Mit Bindestrich nur als Adjektiv:

on-hand inventories.

Ohne Bindestrich als verbale Fügung:

There's no beer on hand.

Lis, don't touch the topic 'hyphens' if you don't want to start a war: GB and USA may agree on nearly everything: tea taxes, slavery, foreign politic, economy... but on THAT point they just won't :)

@Sherlock: Oh darn, I was about to launch a preemptive/pre-emptive strike. ;-)