Dear Cheese,
Yes as you said it is exists, and how basically it work please see below quidelines:
Vouchers can include gift certificates and gift cards. A gift card acts like a debit card. Customers can pre-pay a certain amount towards the gift card and redeem it with whatever value the card is.
Before you use the gift voucher/card you must create first one tender type called voucher and one PLU with type voucher. this way you can seel and redeem voucher at POS. you have also facility to transfer funds from one voucher to another or new voucher.
Voucher system works exactly as serialize item.
How to Sell
------------- When at the POS you wanted to sell the voucher to any customer you will ring up the SKU of voucher which you have created in manager program. Then system will ask you the Serial No (can be created on fly) and enter the value of your gift voucher and select the mode of payment from customer.
How to Redeem
------------------- Customer purchase some goods and wanted to redeem the gift voucher purchases from your store. You will scan all the customer's items then in press F12 to tender the transaction and then select the tender type "Voucher/Gift Card" which you created in Store Manager Program and system then will ask you the Serial No. Remeber system won't accept you the exceed amount it will accept you only the amount you have balance in your voucher.
Last point how do I control the expiration of card. I think it is little bit no avaiable but we can use kind of tools like QSRules.DLL to accomodate this.
If the information help you please rate.