Block a number on iPhone, Android, or landline

The steps to block a number depend on what kind of phone you have. 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 Android, open the Phone app, long-press the number in your call history, and tap "Block number." If you have a landline through a traditional phone company, call your provider's customer service line — they can add numbers to a block list on their end, though the exact process varies by company.

Most phones let you block numbers directly from an incoming call. When a call comes in that you want to block, look for a "Block" or "Decline" option on the call screen itself. This is faster than finding the number later in your history. After you block a number, calls and text messages from that number will no longer reach your phone — they typically go to voicemail or are rejected silently, depending on your phone's settings.

Key Takeaways

  • iPhone users block numbers through the Phone app by tapping the info icon next to a contact or recent call, then selecting "Block this Caller."
  • Android users long-press a number in the Phone app and tap "Block number" from the menu that appears.
  • You can block a number during an incoming call by tapping the block option on the call screen itself.
  • Landline users need to contact their phone company directly, as blocking happens on the provider's network rather than on the device.
  • Blocked numbers cannot reach you by phone or text, though the exact behavior varies slightly between iPhone and Android.

Where to find blocked numbers and unblock them

On iPhone, go to Settings, tap Phone, scroll down to "Blocked Contacts," and you will see every number you have blocked. To unblock someone, swipe left on their name and tap "Unblock." On Android, open the Phone app, tap the three-line menu icon, go to Settings, then Blocked Numbers, and you will see your list. Tap the X or minus icon next to a number to unblock it.

Keep in mind that unblocking a number does not notify the person you blocked — they will not know you have removed them from your block list. The next time they call, the call will go through normally. If you block and unblock numbers frequently, consider using a Do Not Disturb mode instead, which silences calls and texts from everyone except your contacts without permanently blocking anyone.

Blocking unknown or private numbers

If you want to block calls from numbers that show up as "Unknown," "Private," or "No Caller ID," the process is different on each phone type. On iPhone, go to Settings, tap Phone, and toggle on "Silence Unknown Callers." This sends all calls from numbers not in your contacts to voicemail. On Android, open the Phone app, tap the menu, go to Settings, then Blocked Numbers, and look for an option to block "Unknown" or "Private" numbers — the exact wording depends on your phone model and carrier.

Blocking unknown callers is useful if you are getting many spam or robocalls, but it also means legitimate calls from businesses, doctors' offices, or services you have contacted may go to voicemail. You will need to check your voicemail regularly to catch important messages. If unknown calls are a persistent problem, your phone carrier may also offer a spam-blocking service through their own app or network settings.

Using third-party call blocking apps

Beyond your phone's built-in blocking, you can install a dedicated call-blocking app from your device's app store. Popular options include TrueCaller, RoboKiller, and Nomorobo, which block known spam numbers automatically and let you create custom block lists. These apps work by comparing incoming calls against databases of known spam and scam numbers, blocking them before your phone even rings.

Third-party apps often offer more features than your phone's native blocking — for example, they may show you why a number is flagged as spam, let you report new spam numbers to their database, or block calls based on keywords in voicemail messages. However, they require you to grant permission to access your call history and contacts, so review what data each app requests before installing. Some apps are free with ads, while others charge a monthly fee for premium features.

What happens when you block a number

When you block a number on your phone, the blocked caller will not see a notification that they have been blocked. Their call will either ring on their end and then go to your voicemail, or it may fail silently depending on your phone type and carrier. They may not realize they have been blocked — they might assume your phone is off or you are not answering.

Text messages from blocked numbers are handled differently on iPhone and Android. On iPhone, blocked texts are not delivered to you at all, and the sender receives no notification. On Android, blocked texts typically go to a separate folder or are deleted, depending on your phone model. If you block someone and then later unblock them, they will be able to reach you again, but they will not see any record of having been blocked.

Blocking numbers on your carrier's network

In addition to blocking on your device, you can ask your phone carrier to block numbers at the network level. This is especially useful if you are getting repeated calls from the same number or if you want the carrier to handle blocking for you. Call your carrier's customer service number — usually found on your bill or their website — and ask about their call-blocking service. Most major carriers like Verizon, AT&T, and T-Mobile offer this as a free or low-cost feature.

Network-level blocking works the same way as device blocking from the caller's perspective, but it stops the call before it reaches your phone at all. This can be helpful if you are getting harassing calls and want to ensure they do not get through under any circumstances. Some carriers also offer spam-detection services that automatically flag suspected spam calls so you can decide whether to answer.

Blocking numbers when you do not have the full number

Sometimes you want to block a caller but you only have a partial number or you know the business name but not the exact number. On iPhone, you can create a contact with just the information you have, then block that contact. On Android, you may be able to block based on a pattern — for example, some phones let you block all numbers from a certain area code or prefix.

If you know the business name, search for their phone number online and add it to your block list. If you only have a partial number, your phone's blocking feature may not work, but a third-party app might offer pattern-matching or keyword blocking. In cases where you cannot identify the exact number, focusing on blocking unknown callers or using a Do Not Disturb schedule may be more practical than trying to block individual numbers.

Frequently Asked Questions

Will a blocked caller know they are blocked?

No. A blocked caller will not receive a notification that you have blocked them. Their call may ring on their end before going to voicemail, or it may fail silently. They have no way to know for certain whether you blocked them or simply did not answer.

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

Yes. On iPhone, you can block "Unknown Callers" through Settings. On Android, you can block calls from numbers not in your contacts. You can also block a specific number even if you do not know who owns it — just add it to your block list from your call history.

What is the difference between blocking and Do Not Disturb?

Blocking permanently prevents a specific number from reaching you. Do Not Disturb silences all calls and texts for a set time period but does not block anyone — calls still go through, just silently. You can set Do Not Disturb to allow calls from your contacts while blocking everyone else.

Can I block a number on my landline?

Yes, but you must contact your phone company to do it. Call your provider's customer service and ask them to add the number to your block list. They manage blocking on their network, not on your physical phone.

If I unblock someone, will they know?

No. Unblocking a number does not send any notification to that person. They will simply be able to reach you again the next time they call or text, with no indication that you had previously blocked them.