Related: Why does my call ask me to choose another system dialer? Why is the lock missing next to my phone icon? Why can't I make calls?
iOS Users, see information here. Android Users, continue below.
Signal users can
- privately call other Signal users for free over the internet
- insecurely call non-Signal contacts, which incurs costs as set by mobile plans
Signal calls are
- completed over the internet
- free of charge
- available between Signal users
- show a lock icon to the top right to indicate a private call is available
This is what you see if you can start private calls
This is what you see if you only start insecure calls. To make Signal calls to this contact, have him/her register as a Signal user.