Quality Gift Cards can be an expensive investment for any business, so it makes sense to re-use them as your customers clear them out. There are a couple of ways to do this, and only one is recommended as a best practice, although the second method can be best in certain situations.
Method One (Recommended): Delete the Old Card Number First
Go first to Products > Gift Cards and use the Search to find the Gift Card number you are re-using. If it has gone down to a zero balance, you will likely need to check the box for Show Inactive in order to view it. Once you find the card, on the right side, click the X button to delete it. It's okay, we'll be adding it again in the next step.
Go to your Register and click Gift Card, you can scan or enter the Gift Card Code into the panel that comes up. Enter the Title you prefer and the Amount, then click Save to add it to the transaction. Complete the transaction in the normal way.
What this method accomplishes is that it removes the card history from the system. Don't worry, all of the transactions will still be there, but the card number will basically be 'cleaned' so that past history won't interfere if you need to look something up about the card as it is used moving forward. Only new transactions done with the new card balance will be visible from Products > Gift Cards if you click on the card's Code and look at History.
Method Two: Overwrite Old Gift Card Code
You can go to the Register, click the Gift Card button, and simply enter the Code of the card you are re-using. A warning will pop up telling you the card is already in the system (see below). You can then add whatever amount of money is being put on the card and complete the transaction in the normal way.
If the card already has funds on it, the new funds will be added to that total, so if someone is wanting to just 'reload' their card, this would be the ideal method. The purchase history of the card will still be accessible through Products > Gift Cards by clicking on the card's Code.
But if a new customer is buying the card, this may result in confusion for whatever had been bought using the card before. This is the fastest way to put funds on a card and re-use an old one, so if you're not concerned with the history of purchases on the card, this is a great method.