Half.com doesn't state whether coupon codes can be used with other promotions that may take place on the site or with other coupon codes. However, users can try applying the coupon codes to their orders to be notified whether it's acceptable for use or not. This may require having an item in the shipping cart, mentions eBay.com.
Users can enter their coupon codes from the shopping cart page on Half.com, where they can find a box for either a gift certificate number or a coupon. Applying the code to the order shows what discount applies, and an unsuccessful code will show an error message. Users can also check the coupon itself to see if any exclusions apply, or they can reach out to Half.com customer service.