To reduce spam calls on iPhone or Android, use a control for incoming calls: screen unknown callers, silence them, filter calls flagged as spam, or block a specific number. Turning off Show My Caller ID changes whether people see your number when you call them; it does not manage incoming calls. Apple explains the outgoing caller ID setting separately from its incoming-call controls.
Match the control to the caller: screen or silence unknown numbers, filter calls identified as spam, and block a specific number when you recognize it.
On iPhone, choose how unknown callers reach you
Apple offers three choices for calls from unsaved numbers: Never, Ask Reason for Calling, and Silence. Never lets those calls ring normally. Ask Reason for Calling asks the caller for their name and reason before the iPhone rings. Silence sends the call to voicemail. Apple describes how each option works.
Silence does not send every caller to voicemail. Calls from your contacts, recent outgoing calls, and Siri Suggestions continue to ring. Choose it if you want fewer interruptions from numbers you have not saved, but still expect calls from people outside your contacts to reach voicemail.
Ask Reason for Calling has specific conditions: Apple says screening does not work while the iPhone is roaming, and turns off for 24 hours after you call emergency services. On software earlier than iOS 17, Live Voicemail must also be enabled for screening.
Apple also describes a separate spam filter. It silences calls identified as potential spam or fraud by the carrier and sends them to voicemail; availability depends on the carrier. Apple’s guide to screening and blocking calls explains this option.
On Android, filter suspected spam or block one number
Google’s Phone app includes a Filter spam calls setting. Google says calls it filters do not generate missed-call or voicemail notifications. That filtering is different from manually blocking a particular number: it acts on calls classified as spam rather than a number you choose. Google’s Phone app guidance describes the setting.
For a specific example of manual blocking, T-Mobile gives this procedure for a Pixel 6 running Android 12:
- Open Phone and go to Recents.
- Press and hold the number you want to block.
- Choose Block/mark as spam, then Block.
Reporting the number as spam is optional in that flow. T-Mobile’s tutorial says this particular procedure does not block anonymous calls or texts; it describes the Pixel 6 and Android 12 steps, not a universal Android menu path. Read T-Mobile’s Pixel 6 instructions.
Match the setting to the calls you want to manage
| Control | What happens | Practical limit |
| Show My Caller ID on iPhone | Controls whether recipients see your number when you place a call. | It does not manage incoming calls. |
| Ask Reason for Calling on iPhone | The caller gives their name and reason before the iPhone rings. | Screening is unavailable while roaming, pauses for 24 hours after an emergency call, and requires Live Voicemail on software earlier than iOS 17. |
| Silence on iPhone | Unsaved callers go to voicemail. | Contacts, recent outgoing calls, and Siri Suggestions still ring. |
| iPhone carrier spam filter | Silences carrier-identified potential spam or fraud calls and sends them to voicemail. | Availability depends on the carrier. |
| Filter spam calls in Google Phone | Filters calls identified as spam without missed-call or voicemail notifications. | This is spam filtering, not manual blocking of a chosen number. |
| Block a number on Pixel 6 with Android 12 | Blocks the selected number through Phone > Recents. | T-Mobile’s procedure is specific to that device and software version. |
