If you created a gift card/voucher in error, or need to delete it from your system, you can delete it and prevent it from being used.

On the left navigation menu, click on 'Gift Cards':

Search for the gift card/voucher you would like to delete using either the client details or the gift card code:

Click the 'Options' dots for the gift card/voucher you would like to delete and click on the 'Delete' menu option: