How do I use a coupon code at checkout?
If you're a recurring subscriber you can add a discount code in your account.
To add a coupon code - recurring orders
When you're on the order summary page there will a place on the right hand side (as shown below) to add a coupon code; click on the Have a discount code? Enter it here link and enter it in the field provided and hit "Apply", and the discount will apply immediately.
To add a coupon code - one-time orders
The coupon area will be on the payment page, right above the credit card area.
If you're having issues with a coupon code, check to make sure the code has not expired or does not have specific parameters that you need to meet (eg, some codes will only work on recurring subscription orders); you should be able to find this information wherever you received the coupon.