Click price lists in the left sidebar menu in /admin. Locate voucher codes almost at the bottom of the right hand side menu in the price list management site and click to open. Some new features are now added to the voucher codes.
Set the number of times each customer may use the voucher code.
Total number of times the code may be used.
Giving you a list of which orders the voucher code has been used for. Click the links to open order information.
Learn more about voucher codes here.