Printer catridges has to be refilled when the ink is empty on it.You have to refill the ink or change a new one according to its use.You may change atlest once in two or three months depends on the printer usage of you.The refilling ink process ink can be easily done by you.You can also contact the technicians for the ink refilling process of your printer catridge.By following the instruction guide and by using the refilling kits you can refill the ink on your printer catridge. http://www.cheaprefills.info