Check your phone carrier’s call logs or app for the incoming number
Enable caller ID and spam protection features from your carrier
Use call tracing services offered by your carrier
Ask your carrier to block or investigate repeated anonymous calls
Use a third-party call identification app
Report harassment or threats to local authorities
Let the call go to voicemail and review any message left
Do not answer or call back suspicious unknown callers
Contact your carrier to ask about anonymous call unmasking options
Review your phone settings for blocked or hidden caller ID options