How to block unknown numbers on your phone

Last updated: September 29, 2026

Menu names change between phone models and software versions, so use these as a guide.

iPhone

Block one number: open the Phone app, go to Recents, tap the info icon next to the number, then choose Block this Caller.
Silence unknown callers: Settings, Phone, then Silence Unknown Callers. Calls from numbers not in your contacts go to voicemail.

Android

Block one number: open the Phone app, go to Recents, tap the number, then choose Block or Report spam.
Turn on spam filtering: in the Phone app settings look for Caller ID and spam.

Other options

Many mobile carriers offer free or paid spam-call filtering, and Do Not Disturb modes can allow calls only from your contacts. Blocking helps, but scammers often switch numbers, so stay careful with new ones.