Whether a discount code applies to the original price or the sale price usually depends on the store's policy and how the promotion is programmed. Many online stores apply the code to the already reduced sale price, giving shoppers an extra discount during promotions. Others restrict codes to full-priced items only, especially for luxury brands or limited collections. Reading the terms under the promo code or at checkout often reveals these rules before purchase. Sometimes the cart automatically calculates the best eligible discount, while other stores block combining offers entirely. Customer behavior also matters, since shoppers often test multiple codes before buying.