Typically, Diamond Supply allows customers to utilize discount codes on their purchases, provided that the codes are valid and applicable to the items being purchased. It is important to carefully read any terms and conditions that accompany the discount code, as some promotions may be restricted to specific products, categories, or expiration dates. When making a purchase on the Diamond Supply website, you can usually enter the discount code during the checkout process. If you do not see an option for entering a code or if the code does not seem to work, it may be helpful to review the details of the promotion or check for any potential restrictions listed on the website. For the most accurate and up-to-date information regarding promotions and discount codes, it is always best to refer to the official Diamond Supply website.