Why can't I use my coupon code on my order?

There are a couple of reasons you may not be able to apply your coupon code to your order, one is that a code has already been applied, you are unable to use more than one code on an order at a time. The other is that you are placing a subscription order, since subscriptions are pre-discounted and also on a separate system, coupon codes cannot be applied to an order that contains a subscription item.