When either system or user Inhibit Off-Switch Forward/Transfer is enabled, it affects the operation of the user's Phone Manager application and phone. In Phone Manager, the destination fields on the Forwarding tab are changed to drop-down lists containing only internal destinations. User attempts to set an external forward destination via a short code will receive error tone. User attempt to set an external forward destination via a programmable button on their phone will not have a Next option allowing the number to be saved.