Toner yield varies greatly depending on many factors. The model of the machine, coverage on the page, color usage, and frequency of use can all affect the number of pages printed by a toner bottle.
We recommend that all customers keep a spare set of toner (black, cyan, magenta, and yellow for color machines) on hand for emergency situations. When the machine warns you that it is low on toner, locate your spare and make sure it is available for use. When the machine runs out completely replace the empty toner bottle with your spare and continue printing.