Basically there's what the tax man has told them (and everyone else), large companies have put all their rules on the system and pointed to it and said "look mr tax man, only things we specify can be bought with a voucher, no bikes above a thousand pounds or race specific parts", the guy in the shop charges the voucher to a thousand pound bike they sell loads of and does what ever you ask.
This may not be the case if the shop has been audited recently and the manager has got into shit.
Basically there's what the tax man has told them (and everyone else), large companies have put all their rules on the system and pointed to it and said "look mr tax man, only things we specify can be bought with a voucher, no bikes above a thousand pounds or race specific parts", the guy in the shop charges the voucher to a thousand pound bike they sell loads of and does what ever you ask.
This may not be the case if the shop has been audited recently and the manager has got into shit.