Block spam calls on iPhone
iPhone has three separate tools: call screening for unknown numbers, a spam filter that uses your carrier’s spam labels, and a block list for single numbers. The names below are from Apple’s current iPhone User Guide. Older versions of iOS word some of them a little differently.
- Open Settings, tap Apps, then tap Phone.
- Choose how unknown numbers are handled. Ask Reason for Calling makes your iPhone ask the caller who they are before it rings. Silence sends calls from unsaved numbers straight to voicemail; they still show in Recents.
- Turn on Spam. Calls your carrier identifies as potential spam or fraud are silenced, sent to voicemail and moved to the Spam list.
- To block one number, open the Phone app, tap Contacts, tap the contact, then tap Block Contact.
- To check what was filtered, open the Phone app, tap the Filter button, then tap Unknown Callers or Spam.
If a real person ends up in Unknown Callers, tap Mark as Known next to the call so future calls ring normally.
Block spam calls on Android
On phones that use the Phone by Google app (Pixel and many others), caller ID and spam protection is on by default. You can go one step further and filter spam so it never rings.
- Open the Phone app, tap More options, then Settings, then Caller ID and spam.
- Check that See caller ID and spam is on.
- Turn on Filter spam calls. Filtered calls don’t ring or send a missed-call notification, but they stay in your call history and can still leave voicemail.
- To block and report one number, open the Phone app, tap the call, then tap Block or Report spam.
Phones with automatic Call Screen, such as recent Pixels, don’t show a Filter spam calls switch. Spam blocking is one of the Call Screen options instead.
Samsung and some other phone makers ship their own phone app. Samsung’s spam tool is called Smart Call. Look in the phone app’s settings for blocking and spam options.
Add your carrier’s spam tools
Your carrier sees calls before your phone does, so its filter can catch numbers your phone doesn’t know about yet. The FCC lists these tools from the major US carriers: AT&T ActiveArmor, T-Mobile Scam Shield and Verizon Call Filter. It also lists third-party apps such as Hiya, Nomorobo and YouMail.
Check your carrier’s app or website to see which features come with your plan and which cost extra.
| Tool | What it does | Best for |
|---|---|---|
| iPhone Silence or Ask Reason for Calling | Screens or silences numbers that aren’t in your contacts | Personal phones where strangers rarely call |
| iPhone Spam filter | Silences calls your carrier flags as spam or fraud | Everyone |
| Android Filter spam calls | Keeps suspected spam from ringing | Everyone on Phone by Google |
| Carrier app (ActiveArmor, Scam Shield, Call Filter) | Labels and blocks spam on the network | Extra protection on top of the phone’s filter |
| Blocking one number | Stops that exact number | Repeat callers that get through |
Register on Do Not Call and report the rest
Put your numbers on the National Do Not Call Registry. It’s free at donotcall.gov, or call 1-888-382-1222 from the phone you want to register. Legitimate telemarketers agree not to call numbers on it. Scammers ignore it, which is why you still need filters.
Report illegal calls and texts to the FCC (choose “unwanted calls”) and scams to the FTC at reportfraud.ftc.gov. Most carriers also let you forward spam texts to 7726 (SPAM).
The FCC’s own advice: don’t answer numbers you don’t know, hang up if a caller asks for money or personal information, and never pay with gift cards because someone on the phone told you to.
Why “silence unknown callers” is risky for a business
If your number is on your truck, your website or Google, most of your new customers are unknown numbers. Silencing them sends real jobs to voicemail along with the robocalls.
A better setup for a business line is to label likely spam, block the repeat offenders, and let something answer the unknown callers instead of silencing them.
That’s how 2Line.AI handles it. Likely spam is labelled before your phone rings. You can block or unblock any number in one tap, with undo. Unknown callers can go to Mia, the AI receptionist, who asks who’s calling and why and leaves you a written slip. Blocking and spam labels cost nothing, and blocked numbers never get missed-call texts or reminders.
Sources (checked October 2026): Apple: Screen and block calls on iPhone; Google: Use caller ID and spam protection; FCC: Call blocking tools and resources; FCC: Stop unwanted robocalls and texts.