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Step-by-step guide

How to Block a Number on iPhone and Android

Short answer

Both phones let you block a specific number straight from your recent calls or contacts. That stops that one number from ringing you again. It does not stop spammers who switch numbers, so this page also shows what blocking really does and what to pair it with.

Show me the block steps

We never ask for your number or contacts. You do this in your own phone's settings.

Your phone's own tools
Every step uses the built-in Phone app on iPhone or Android, or your carrier's own app.
Defense, not lookup
This helps you block and report calls you received; it can't identify who owns a number.
Independent guide
CallerCheck isn't affiliated with Apple, Google, or any carrier; menus change, so follow what your screen shows.

Block, silence, or report: which tool does which job

Blocking one number, silencing all unknowns, and carrier scam-blocking are three different tools.

Scroll the table sideways on a small screen.

Option Block one numberSilence or filter unknown callersAuto-block known scam callsReport a call as spam
iPhone (built-in) Supported

Recents or a contact card, then Block Caller.

 Supported

Screen Unknown Callers (Silence Unknown Callers on older iOS) can send unsaved numbers to voicemail.

 Conditions apply

Call Filtering can sort suspected spam into a Spam list; labeling depends on your carrier and iOS version.

 Not available

No built-in report-a-spam-call button; use your carrier's app or the FTC.
Android (Phone by Google) Supported

Tap the call in Recents, then Block or Report spam.

 Conditions apply

Filter spam calls quiets suspected spam, not all unknown numbers; some dialers can also block hidden or unidentified callers.

 Conditions apply

Caller ID and spam labels suspected calls; advanced detection needs a recent Android and the Google apps.

 Supported

Block or Report spam usually offers a report checkbox.
Samsung Galaxy (One UI Phone app) Supported

Open the call in the Phone app and look for a block option; wording varies by One UI version.

 Conditions apply

Block numbers, and turn on blocking unknown or hidden callers where your dialer offers it.

 Conditions apply

Samsung's dialer has its own spam settings; names and availability vary by region and version.

 Supported

Choose report as spam when you block, where the dialer offers it.
Third-party caller-ID app (iPhone or Android) Supported

Add numbers to the app's block list after you grant it call-blocking permission.

 Conditions apply

Some apps can filter or send flagged and unknown callers to voicemail.

 Supported

Shared spam lists warn about or auto-block widely reported numbers.

 Supported

Report a number to the app's community spam database.
Your carrier (T-Mobile / Verizon / AT&T) Conditions apply

Some carrier apps keep a personal block list; details vary by carrier and plan.

 Not available

Silencing all unknown callers is a phone setting, not a carrier feature.

 Supported

Free carrier services label or auto-block likely scams — see the carrier guide.

 Supported

Report a number in your carrier's spam-block app.

Note: Features, menu names, and prices vary by carrier, plan, OS version, and region, and change over time. MVNOs and prepaid brands may offer a subset or none of a carrier's service. Check the official page before relying on any option.

checked September 2026

Block a specific number in a few steps

The wording differs by phone, but the path is the same: open the call, then choose block.

Steps vary by OS version and phone maker; Samsung and other Android dialers use their own menu names. Look for caller ID, spam, or blocked numbers if yours differ.

  1. Open your recent calls

    iPhone: Phone app, Recents. Android: Phone app, Recents or the calls list.

  2. Tap the number or contact

    From Recents or a contact card; on iPhone you can also add one via Blocked Contacts in settings.

  3. Choose block

    iPhone: scroll down to Block Caller. Android: tap Block or Report spam.

  4. Report it too, if offered

    On Android, leave the report-as-spam box checked so the label improves for others.

  5. Review your blocked list

    Manage or unblock later under Blocked Contacts (iPhone) or Blocked numbers (Android).

See what blocking does and doesn't do →

A contact screen for an unknown number with the “Block this caller” button highlighted in two steps.
Illustration, not a real phone interface.

When blocking one number isn't enough

A block stops one number, but spam callers change numbers and caller ID can be faked.

  • The same scammer keeps calling from new numbers

    The FTC warns scammers fake and switch caller ID numbers, so your block list never catches up.

    Instead: Turn on Screen Unknown Callers (Silence Unknown Callers on older iOS) or your Android spam filter, and add your carrier's scam blocking on top.

  • A blocked caller still left a voicemail

    Apple says a blocked caller can still leave a voicemail; you just get no notification.

    Instead: Ignore it, or check the blocked-voicemails area occasionally for anything real.

  • The number showing on caller ID looks local or official

    Caller ID is spoofable, so blocking that display number may block a real one later.

    Instead: Treat caller ID as unproven; block, but verify a business by a number you look up yourself.

  • The call shows No Caller ID or Unknown

    There is no number attached, so there is nothing to add to a block list.

    Instead: Turn on Screen Unknown Callers (Silence Unknown Callers on older iOS) or your Android spam filter, and report it at donotcall.gov (or reportfraud.ftc.gov if you lost money); lean on carrier auto-blocking too.

  • You think you blocked the wrong number

    A misdialed block hides a caller you actually wanted.

    Instead: Open Blocked Contacts on iPhone or Blocked numbers on Android and unblock it.

  • You want to stop most spam, not just one caller

    Blocking is one-at-a-time; it can't cover the whole flood of spam.

    Instead: Layer phone filters and your carrier's scam blocking; the Do Not Call Registry only curbs legitimate sales calls.

Questions people ask

What happens to a caller after I block their number?

Apple says a blocked caller can still leave a voicemail, but you won't get a notification, and calls and texts won't come through. The blocked person isn't told that the call or message was blocked. On Android, what happens to a blocked caller's voicemail varies by dialer and carrier; check your Phone app's help.

Does blocking a number stop all the spam calls?

No. Blocking stops that one number. The FTC notes scammers spoof and rotate numbers, so a persistent spammer can just call from a new one. Pair blocking with silence-unknown or spam filtering and your carrier's scam-blocking service.

Where do I unblock a number I blocked by mistake?

On iPhone, open your Blocked Contacts list (in your Phone or Privacy settings) and remove it. On Android's Phone by Google app, go to Settings, then Blocked numbers, and unblock it. Menu names vary by OS version and phone maker.

Can blocking a number tell me who was calling?

No. Blocking only stops future calls from that number. It can't reveal who owns a number, and caller ID is not proof of identity because it can be faked. This site helps you block and report calls, not look up a caller's identity.

Does blocking a number also block its texts?

On iPhone, blocking a number or contact also stops its messages and FaceTime calls. On Android, blocked numbers usually apply to both the Phone and Messages apps, but this varies by phone maker and messaging app, so check your Messages settings. Spam texts are covered in our text message guide.