We understand your Brother TN850 cartridge did not last long. We'd like to help. The stated page yields for genuine Brother cartridges are based on the ISO testing standards. The number of pages that can be printed with a cartridge is affected by several factors, including paper size, number of pages per print job, amount of print on each page, font size, and print content (graphics, charts, etc.). Print jobs with large text fonts, graphics, charts, and/or large amount of solid coverage (black or any given color) will use much more toner and will shorten the life of the toner cartridge. If you have any questions about your Brother Genuine cartridge, please contact Brother customer service: https://www.brother-usa.com/brother-support

We understand that you are unhappy with the page yield of the Brother TN-850 toner cartridge and we'd like to help. This toner cartridge yields approximately 8,000 pages based on the ISO/IEC 19752 testing standards. The number of pages that can be printed with a cartridge is affected by several factors, including paper size, number of pages per print job, amount of print on each page, font size, and print content. Print jobs with large text fonts, graphics, charts, and/or large amount of solid coverage will use much more toner and, naturally, will shorten the life of the toner cartridge. If you that you have printed less pages than advertised, feel free to contact Brother Customer Service directly at https://www.brother-usa.com/support

Thanks for taking the time to review your experience with the Brother TN850. We appreciate your feedback. If you still need assistance, we would like to help. Please contact the Brother USA support team at: https://www.brother-usa.com/support

We would like to take this opportunity to thank you for your feedback. We are sorry to hear that you did not get the toner yield as expected with your Brother TN850. At Brother, customer satisfaction is something we take seriously. Your feedback is important to us and will be reviewed to help us improve our future products. Genuine Brother toner cartridges are produced with a specific amount of toner to yield the following: TN inbox toner cartridge - approx. 12,000 pages* TN820 toner cartridge - approx. 3,000 pages* TN850 toner cartridge - approx. 8,000 pages* TN880 toner cartridge - approx.12,000 pages* TN890 toner cartridge - approx.20,000 pages* The approximate toner yield is in accordance with ISO/IEC 19752. The number of pages that can be printed with a toner cartridge is affected by several factors, including paper size, number of pages per print job, amount of print on each page, font size, and print content, such as graphics, charts, etc. It is important to know that a typical printed document is one letter-sized (8.5" x 11") page with 4% - 5% print coverage. If you need more assistance, we would be glad to help you. Our Brother customer support team is available to assist you directly at www.brother-usa.com/brother-support.