Hello Tom,
You are correct if you try to install toner for the 6350 into the 6300 printer you will get a incompatible error message.
Hi, I'm the original owner of a Phaser 6300DN. The printer works perfectly but it is increasingly dificult to find Xerox brand toner. Does anyone know if the toner for the Phaser 6350 models will work? The cartredges appear to be very similar. If it fits, will the 6300DN printer reject the 6350 toner because the 6350 tonr cartridge chip is incompatible with the 6300? Thanks!