A promo code is a series of letters, numbers, or both that customers can enter at checkout to receive discounts or special offers on their purchases. These codes are often provided by retailers to encourage sales, promote new products, or reward loyal customers. When a customer applies a promo code, the discount is typically deducted from the total price, making the purchase more affordable. Promo codes can be found on various platforms, including websites, social media, and email newsletters, and they usually have expiration dates or specific terms of use associated with them.