Samsung: Block Unknown and Private Callers Automatically

Samsung phones ring for every incoming call by default, even when the caller has suppressed their number or the network cannot identify it. This is common with spam calls, robocalls, and callers using private number settings.

One UI includes a built-in option that rejects these calls automatically, without needing a third-party app. It works at the system level in the Phone app settings, so it applies to every incoming call, not just contacts.

To turn it on: Tap on Phone ➤ Open the Menu ➤ Tap on Settings ➤ Tap on Block numbers ➤ Turn On/Off Block unknown/private numbers.

Once enabled, calls without a visible number never reach your ringtone or lock screen. They usually appear in the call log as blocked or rejected, depending on your region and carrier.

This setting is not the right fix if you expect calls from services or delivery drivers who often mask their number for privacy reasons. In that case, blocking unknown callers might cause you to miss important calls, and using individual number blocking instead is safer.

Side effect: this option blocks all hidden numbers indiscriminately. It cannot distinguish between a spam call and a legitimate business calling from a private line.