Catfish allows users to enter discount codes at the shopping basket to apply discounts to their order.
The code entry box shows at the bottom of the basket page.
The discount entry field is assigned to each storefront by default.
To switch it off, login as an administrator to the storefront you wish to change. choose: Configuration -> Shopping Basket Settings
Locate the option Show Discount Box and untick the option.
Save your changes and return to the shopping basket where the field is removed.