We have purchased a few extra phones to add to our system. I am trying to program a "Voice Mail Transfer" button on one of the flexible keys and cannot find the code to program in. When I check the programming of other phones already installed, the display "VMT Key 600" comes up. Any suggestions?

OK, at the phone press the on/off, press program, press the button that you're trying to program, press conf, auto, auto, 600, then press hold and on/off.

This should work for you.