AOS INTL LLC has a 365 Day Warranty from the date of purchase for all customers who are on a contract with AOS for there imaging supplies and products. For those customers only, should you change printers during this time, AOS will exchange your unused toner as a credit towards the new toner needed by the customer. AOS does not offer full refunds on these established accounts, but is more than happy to exchange product as you change your imaging equipment. AOS products have undergone rigorous, incoming quality control testing procedures before shipping. Product lines and primary factories are certified under the ISO 9001/9002 Quality System as well as being STMC Certified. The cartridges and products are guaranteed to be free from defects in both material and workmanship from original date of purchase for a period of one year or until the product is depleted, whichever occurs first. Our guarantee to you is that our NEW OEM PRIVATE LABEL Compatible replacement cartridges will perform equal to or better than the OEM product. Our advanced cartridge technology involves a state-of-the-art manufacturing process which includes graphics quality toner and OPC drums. The result is a cartridge that produces darker prints and sharper graphics, to meet the highest standards of each and every customer. All cartridges are quality tested during the manufacturing process. Additionally, they are post-tested once assembly is complete.