For one person: their profile → Chat settings → Allow calls:
- All calls — voice and video.
- Voice only — your phone rings for their voice calls, but you get no video calls from them. If they tap "Video" they see "… only accepts voice calls" with a Voice call button.
- No calls — their calls never reach you (and aren't logged as missed). They see that you aren't taking calls right now, and can still message you.
For a whole circle: People → Circles → the circle → Circle rules → Can call me — the same three options for all its members (for example: your Work circle on "Voice only"). If someone is in more than one circle, the strictest rule applies.
It's enforced on the server — a blocked call never reaches you, even if their app is old.
Also:
- Blocking stops everything: messages, voice and video calls.
- Do not disturb (from your status): calls arrive silently, except from circles allowed to bypass "Do not disturb".