If the website states that your discount code is invalid, these are the most common reasons, in order:
One of the items (or sizes) you are trying to buy has already been discounted. Discount codes will only work on full price products. If the item (or specific size) is discounted, you'll see the old price with strike through it.
The code is not applicable to the product that you are trying to purchase. Most of our codes are only valid for a particular product or range (e.g. Summer Range). Please double check that you are using the code on a valid product. There is usually a link to the correct product/range inn the place you found the discount code itself (eg the promotional email you received)
The code has expired. Most codes are only valid for a limited period. The period should be stated where you received the code.
The code has been entered incorrectly. To ensure the code has been typed correctly, please copy and paste the code into the voucher code box, and click 'Apply Coupon'.
Please note that codes can not be used on subxcription products or in conjunction with store credit - in these instances the discount code box is not visible.