Why can Unicom answer the phone for free?

1. Unicom's mobile phone card will not be able to make calls, send text messages, surf the Internet and order value-added services if it is stopped (one-way stop). But you can answer the phone and receive text messages.

2. Unicom mobile phone card arrears (two-way downtime) will not be able to answer the phone, send and receive short messages, surf the Internet and order value-added services.