The basic steps differ by phone type, but all modern phones let you block numbers directly in the phone app

Blocking a call means that person cannot reach you by phone — their calls go straight to voicemail, and you will not see a missed call notification. On an iPhone, you open the Phone app, find the number in your recent calls or contacts, tap the info icon, and select "Block this Caller". On an Android phone, open the Phone app, long-press the number, and tap "Block number". Both methods take about 10 seconds and do not require any special app or service.

The blocked person does not get a message saying they are blocked. Their call straightforward fails to ring through to you, and they hear a message that varies by carrier — sometimes a generic "the call cannot be completed", sometimes a busy signal. They may assume your phone is off or you are on another call. You will not see their calls in your recent list, though some phones let you view a separate blocked calls log if you want to check later.

Key Takeaways

  • iPhone users block numbers through the Phone app by tapping the info icon next to a recent call or contact, then selecting "Block this Caller".
  • Android users long-press a number in the Phone app and tap "Block number" to prevent that caller from reaching them.
  • Blocked callers hear a generic message and do not receive notification that they are blocked.
  • You can unblock a number at any time using the same method, and the person can then call you normally again.
  • Blocking works only on your device — the person can still text you, email you, or reach you through other apps unless you block them there too.

Blocking a number on iPhone

Open the Phone app and go to the Recents tab at the bottom. Find the number you want to block — it can be a recent call or a contact you have saved. Tap the small circle with an "i" on the right side of that entry. Scroll down to the red "Block this Caller" button and tap it. A confirmation message will appear; tap "Block Contact" to confirm.

If you want to block someone who is already in your Contacts, you can also open the Contacts app, find their name, tap "Edit" in the top right, scroll to the bottom, and tap "Block this Caller". Either way takes the same amount of time. Once blocked, their number will no longer appear in your recent calls list, though you can view all blocked numbers by going to Settings > Phone > Blocked Contacts.

Blocking a number on Android

Open the Phone app and go to the Recents or Call History tab. Long-press (hold your finger on) the number you want to block until a menu appears. Tap "Block number" or "Block contact" — the exact wording depends on your phone manufacturer and Android version. A confirmation message will pop up; tap "Block" to confirm. The number is now blocked.

If the number is saved in your Contacts, you can also open the Contacts app, find the person, tap the three-dot menu, and select "Block number". To see your full list of blocked numbers, open the Phone app, tap the three-line menu (hamburger icon), and look for "Blocked numbers" or "Blocked contacts". The exact location varies slightly between Samsung, Google Pixel, and other Android phones, but the feature exists on all of them.

What happens when you block someone

A blocked person's calls go directly to your voicemail without your phone ringing. They will not see a message saying they are blocked — instead, they hear a standard message from your carrier that sounds like a regular failed call. Some carriers play a busy signal; others say "the call cannot be completed as dialed". The blocked person may think your phone is turned off, you are on another call, or your voicemail is full.

Text messages from a blocked number still arrive on your phone, but you will not get a notification. The messages sit in your conversation thread, and you can read them if you choose to unblock the person later. Blocking a phone number does not block text messages, emails, or messages through apps like WhatsApp or Facebook Messenger — you have to block the person separately in each service if you want to stop all contact.

Unblocking a number if you change your mind

On iPhone, go to Settings > Phone > Blocked Contacts. Find the number you want to unblock and swipe left on it (or tap "Edit" and then the minus sign). Tap "Unblock". On Android, open the Phone app, tap the menu, find "Blocked numbers", long-press the number you want to unblock, and tap "Unblock". Once you unblock someone, they can call you normally again, and their calls will ring through to you.

Unblocking does not notify the person that you have unblocked them — they straightforward regain the ability to reach you. If they tried to call while they were blocked, they will not see those failed attempts once you unblock them. You can block and unblock the same number as many times as you need to.

When blocking is not enough

If you are receiving repeated unwanted calls from different numbers, blocking each one individually becomes tedious. Many carriers offer a separate spam-filtering service — AT&T Call Protect, Verizon Call Filter, and T-Mobile Scam Shield are built into those carriers' networks and catch many spam calls before they reach you. These services are often free or cost a few dollars per month. You can turn them on through your carrier's website or app.

If someone is harassing you through repeated calls, texts, or messages across multiple platforms, blocking individual numbers may not be enough. Document the pattern (dates, times, what was said) and consider reporting it to local police or your carrier's abuse team. If the harassment involves threats, most carriers and platforms have formal reporting processes that can escalate the issue beyond straightforward blocking.

Blocking calls from unknown or private numbers

Some phones let you block all calls from numbers that do not show up in your contacts or that are marked as "Unknown" or "Private". On iPhone, go to Settings > Phone > Silence Unknown Callers. This sends calls from unknown numbers straight to voicemail without ringing your phone. On Android, the option varies by manufacturer — look in the Phone app settings for "Block unknown" or "Block private numbers", or check your carrier's app for spam-filtering options.

Be aware that blocking all unknown numbers means you might miss important calls from doctors' offices, schools, or businesses that call from main switchboards. A safer middle ground is to use your carrier's spam filter, which catches most robocalls and spam while still letting legitimate calls through.

Frequently Asked Questions

Can someone tell if I have blocked them?

No. A blocked person hears a standard "call cannot be completed" message that sounds like any other failed call. They have no way to know whether you blocked them, your phone is off, or you are on another call. They may suspect it if you never respond to calls or texts, but the phone system does not tell them.

Will blocked calls go to my voicemail?

Yes. Blocked calls go straight to voicemail, and the blocked person can leave a message. You will not be notified of the voicemail, but it will be stored in your voicemail inbox if you choose to check it later. Some people delete these voicemails without listening; others keep them for documentation.

Can I block a number if I do not know who it is?

Yes. You can block any number that appears in your recent calls, even if it is not saved in your contacts. You do not need to know who the person is — if you do not want to hear from that number again, you can block it when ready.

Does blocking work across different phone apps?

No. Blocking a number in your phone's native Phone app only blocks calls and voicemail. Text messages, WhatsApp, Facebook Messenger, and other apps have their own blocking features. You have to block the person separately in each app if you want to stop all contact with them.

What if someone calls me from a different number after I block them?

Blocking one number does not stop someone from calling you from a different phone or number. If someone is determined to reach you, they can use a friend's phone, a work line, or a different device. If this is happening repeatedly, it may be harassment, and you should document it and contact your carrier or local police.