Promotional codes must be entered during the "checkout". In order to use it, you only need to enter your promotional code in the box on the right side of the checkout page and click "Apply". You will see the discount applied, if not (invalid code, run code) an error message will be displayed. Promo codes cannot be applied to existing orders, transfer or redeem for cash, credit or previous purchases. Certain products are excluded from promotion: see the specific terms of the promo code before applying it. If you have any questions about promotions or need assistance in placing your order, please contact us.