Promo codes are entered are on the check out screen where you select payment method. Codes & coupons only work for a limited time! If you get an error, it may have maxed the color/size you selected.. so try another one. Sometimes it helps to check out one item at a time! SCREENSHOT TO EASILY COPY/PASTE PROMO CODE AT CHECKOUT! LTKootd LTKMidsize LTKSaleAlert