is usually 0000 or 1234 or last four digits of current phone NEC TalkTime 800 Func 9 Func Mem 7 6 Mem # 0 1 Mem # 7 1 # (shows old number) # # # # 0? # ?? (I stopped taking notes - I think I had to hold down clear to get back to the test menu, then 02# or some such dropped back to the normal menu, and my phone had the new number)