The basic steps depend on your phone type and carrier

Most phones let you block a number directly from your call history or contacts. On an iPhone, open the Phone app, find the number you want to block in your recent calls, 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." Your carrier may also offer blocking through their network, which stops calls before they reach your phone — useful if the caller spoofs their number or if you want to block calls even when your phone is off.

The method you choose matters because phone-level blocking and carrier-level blocking work differently. Phone-level blocking is free and immediate but only works when your device is on. Carrier-level blocking (sometimes called network blocking) stops calls at the carrier's equipment, so it works even if your phone is powered down or in airplane mode. Some carriers charge a small monthly fee for this service, while others include it free.

Key Takeaways

  • iPhone users can block a number through the Phone app by tapping the info icon next to a recent call and selecting "Block this Caller."
  • Android users long-press a number in their call history and tap "Block number" to prevent that caller from reaching them.
  • Your phone carrier offers network-level blocking that stops calls before they reach your device, which works even when your phone is off.
  • Third-party apps like Nomorobo, RoboKiller, and Truecaller can block spam and robocalls automatically, though some charge a subscription fee.
  • Blocking a number prevents calls and texts from that caller, but they may not know they have been blocked.

Blocking on iPhone

Open the Phone app and go to the Recents tab. Find the number you want to block, tap the blue info icon (circle with an "i") next to it, scroll down, and tap "Block this Caller." The number is now blocked on your device. If you want to block someone from your Contacts app instead, open Contacts, select the person, tap "Block this Caller" at the bottom of their card, and confirm.

You can also block a number from a text message. Open the Messages app, find the conversation, tap "Details" in the top right, and select "Block this Caller." Once blocked, calls and texts from that number will no longer reach you, and the caller will not receive a notification that you blocked them — their call will simply not go through.

To see your blocked list or unblock someone, go to Settings, tap Phone, scroll down to "Blocked Contacts," and review the numbers you have blocked. You can tap "Edit" and remove anyone from the list.

Blocking on Android

Open the Phone app and go to your call history. Long-press the number you want to block until a menu appears, then tap "Block number." Confirm the action, and that number is now blocked. If you prefer to block from your Contacts app, open Contacts, select the person, tap the three-dot menu, and choose "Block number."

You can also block a number from a text message. Open Messages, find the conversation, long-press it, and tap "Block" or "Block number" depending on your phone manufacturer. Like iPhone, blocked callers will not know they are blocked — their calls simply will not ring through.

To view or unblock numbers, open the Phone app, tap the three-dot menu, select "Settings," then "Blocked numbers." You can tap any number and choose to unblock it.

Carrier-level blocking through your phone company

Your carrier — whether Verizon, AT&T, T-Mobile, or another provider — can block numbers at their network level. This stops calls before they reach your phone, even if your device is off. Contact your carrier's customer service or log into your online account to set up network blocking. Some carriers offer this free, while others charge $2 to $5 per month.

Verizon offers "Call Filter" (free basic version, paid premium version with more features). AT&T offers "Call Protect" (free basic version, paid version available). T-Mobile includes "Scam Shield" free for most customers. Each service lets you block specific numbers and often includes automatic spam detection. Ask your carrier which service they offer and whether it is included in your plan.

Using third-party blocking apps

Apps like Nomorobo, RoboKiller, Truecaller, and Whoscall can block calls and texts automatically. These apps maintain databases of known spam and robocall numbers, so they can block calls you have not personally reported. Some are free with limited features, while others charge a monthly subscription ($3 to $10 per month is typical) for full protection.

Download the app from your phone's app store, grant it permission to access your calls and contacts, and it will begin filtering incoming calls. Most apps let you add custom numbers to block as well. The trade-off is that these apps use your phone's resources and may slow it slightly, though most users do not notice a difference.

If you use an iPhone, note that third-party apps cannot block calls at the system level the way Apple's built-in blocking does — they can only filter and warn you about suspicious calls. Android apps have more access to your phone's call system, so they can block more effectively.

What happens when you block a number

When you block a number on your phone, calls from that number will not ring through to you, and you will not receive a notification that they called. Text messages from that number will not appear in your main message thread. The blocked caller will not hear a message saying they are blocked — their call will simply not connect, and they may hear a generic message or silence.

Blocking is not permanent. You can unblock a number at any time through your phone's settings or your carrier's app. If someone calls you from a different number, you will still receive that call even if you have blocked their other number, so blocking is useful for a specific phone number rather than a person.

Blocking spam and robocalls

If you receive calls from numbers that change frequently or that you do not recognize, blocking individual numbers is not practical. Instead, enable your phone's built-in spam detection. On iPhone, go to Settings, Phone, and toggle on "Filter Unknown Senders" — this sends calls from numbers not in your contacts to voicemail. On Android, open the Phone app, tap the three-dot menu, go to Settings, and enable "Spam and Call Screen" or "Filter Spam."

For more aggressive filtering, use a third-party app or your carrier's spam-blocking service. These tools use machine learning to identify robocalls and spam patterns, blocking them before they reach you. They are more effective than manual blocking for spam because they adapt to new spam tactics.

Frequently Asked Questions

Can someone tell if I blocked them?

No. When you block a number, the caller will not receive a message saying they are blocked. Their call will not connect, and they may hear silence, a busy signal, or a generic message depending on your carrier. They have no way to know for certain that you blocked them rather than simply not answering.

What is the difference between blocking and muting notifications?

Blocking stops calls and texts from reaching you entirely. Muting notifications (or silencing a contact) lets calls and texts through, but your phone does not ring or alert you — they go straight to voicemail or appear silently in your message thread. Use muting if you want to avoid interruptions but still see the messages later.

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

Yes. You can block any number from your call history, even if it is not in your contacts. Open your recent calls, find the unknown number, and block it. If you receive many calls from unknown numbers, enable your phone's spam filter instead, which is faster than blocking each number individually.

Will blocking stop text messages too?

Yes. When you block a number on your phone, both calls and text messages from that number are blocked. On some carriers, you can set up separate rules for calls and texts through their network-blocking service, so check your carrier's app if you want different rules for each type of contact.

Can I block a number from my carrier if I do not have their app?

Yes. Call your carrier's customer service number (usually on your bill or their website) and ask them to block a specific number at the network level. They can do this over the phone without requiring you to download an app, though using their app is usually faster for managing multiple blocked numbers.