Sony SPP-A985 - Manual (Page 58)

58 US Answering Machine Features
Operating from an outside phone
Setting the remote ID code (security code)
To operate the answering machine from a touch-tone phone while you
are away from home, you need to set the remote ID code (security
code).
1
Press (MENU) repeatedly until
you hear “Set security code”.
2
Press (SELECT) to change the
remote ID code (security code)
setting.
3
Press (TIME/SET) to confirm
your choice.
The new remote ID code
(security code) is announced.
4
Press (PLAY/STOP) to exit the
menu setup mode.
Note
Press and hold (SELECT) to increase the remote ID code (security code) by 10.