The fastest way depends on your phone type
Blocking a number works differently on Android than on iPhone, and some phones have built-in tools while others rely on your carrier or a third-party app. The simplest method on most phones is to open the call log, find the number you want to block, and tap a block or report option — no app read needed. If that option does not appear, your phone's settings menu or your carrier's website will have a blocking feature.
Some carriers like Verizon, AT&T, and T-Mobile offer their own blocking services, either free or for a small monthly fee. These work across any phone on that network. If you want to block many numbers at once or block calls based on patterns (like all unknown numbers), a third-party app may be faster than blocking one at a time.
Key Takeaways
- On iPhone, open the Phone app, find the number in your recent calls, swipe left, and tap Block This Caller.
- On Android, open the Phone app, long-press the number in your call history, and select Block or Block Number.
- Your carrier (Verizon, AT&T, T-Mobile, etc.) may offer free or paid blocking tools that work on any phone on their network.
- Third-party apps like Nomorobo, RoboKiller, and TrueCaller can block spam patterns and unknown numbers automatically, though some charge a monthly fee.
- Blocking a number prevents calls and texts from that number, but the caller will not receive a notification that they are blocked.
Blocking on iPhone
Open the Phone app and go to the Recents tab at the bottom. Find the number you want to block, tap the information icon (a small circle with an i), scroll down, and tap Block This Caller. The number is now blocked — calls and texts from it will not reach you, and it will not ring or notify you.
If you want to block a number that is not in your recent calls, open Contacts, find the person, tap the information icon, scroll down, and tap Block This Caller. You can also block a number while a call is happening by tapping the red phone icon to end the call, then tapping the information icon that appears and selecting Block This Caller.
To see your blocked list or unblock a number, go to Settings, tap Phone, scroll down to Blocked Contacts, and tap Manage Blocked Contacts. From here you can add numbers manually or remove blocks.
Blocking on Android
Open the Phone app (the default dialer that came with your phone) and go to the Recents or Call History tab. Long-press the number you want to block until a menu appears, then tap Block or Block Number. Some Android phones use slightly different wording — look for options like Report and Block or Add to Block List.
If the number is in your Contacts, open Contacts, find the person, tap the three dots or menu icon, and select Block Number. If you want to block a number that is not in your call history or contacts, open the Phone app, go to the menu, find Settings or Call Settings, and look for a Blocked Numbers or Blocked Calls section where you can type in a number manually.
To view or unblock numbers on Android, go to the Phone app menu, select Settings, then Blocked Numbers or Blocked Calls. Tap any number to unblock it. The exact path varies by manufacturer — Samsung, Google Pixel, OnePlus, and others place this setting in slightly different locations, but all have it somewhere in the Phone app settings.
Using your carrier's blocking service
Verizon offers Call Filter free with basic blocking, or Call Filter Plus for a monthly fee that adds spam detection. AT&T offers Call Protect free with basic blocking, or Call Protect Plus for a fee. T-Mobile includes Scam Shield free with basic blocking and optional paid upgrades. These services block calls before they reach your phone and work on any device on that network.
To set up carrier blocking, visit your carrier's website or open their official app. You can usually block a specific number, block all unknown callers, or block calls from certain regions. Some carriers let you create a whitelist of numbers that always get through. Carrier blocking is useful if you want the same block list across multiple phones or if your phone's built-in blocking is not working well.
Third-party apps for blocking spam and unknown numbers
If you want to block entire categories of calls — like all unknown numbers, all international calls, or calls matching spam patterns — a third-party app may be faster than blocking numbers one at a time. Nomorobo, RoboKiller, and TrueCaller are the most common options and work on both iPhone and Android.
Nomorobo is free and blocks known spam numbers using a crowdsourced database. RoboKiller costs money but uses artificial intelligence to identify spam before it reaches you. TrueCaller is free with ads and shows caller names for unknown numbers, letting you decide whether to answer. Most of these apps require permission to access your call history and contacts, so read what they ask for before installing.
Third-party apps can be useful for heavy spam, but they add another layer of software to your phone. Start with your phone's built-in blocking and your carrier's service — they handle most spam without needing an extra app.
What happens when you block a number
When you block a number, calls from that number will not ring your phone and will not show up in your call log. Text messages from a blocked number will not appear in your Messages app. On iPhone, blocked callers will hear a message saying the call could not be completed. On Android, the behavior varies — some phones send blocked calls to voicemail, others straightforward disconnect them silently.
The person calling a blocked number will not receive a notification that they are blocked. They will straightforward experience what feels like a normal failed call or unanswered phone. If they leave a voicemail, it may or may not be delivered to your voicemail inbox depending on your phone and carrier.
Unblocking a number
On iPhone, go to Settings, tap Phone, tap Manage Blocked Contacts, find the number, and swipe left and tap Unblock. On Android, open the Phone app, go to Settings, find Blocked Numbers or Blocked Calls, find the number, and tap Unblock or Remove. Once unblocked, calls and texts from that number will come through normally again.
If you unblock a number and then want to block it again, you can use the same process. There is no limit to how many times you can block and unblock the same number.
Frequently Asked Questions
Can I block a number if I do not know who it is?
Yes. On iPhone or Android, you can block any number whether or not it is in your contacts. If you do not have the number saved, find it in your call history, tap the information icon, and select block. You can also type a number manually into your phone's blocked list if you know the number but it has not called you yet.
Will the person know I blocked them?
No. They will not receive a notification that they are blocked. When they call, they will experience a normal failed call — it may ring once or go straight to voicemail depending on your phone and carrier. They have no way to know whether you blocked them, ignored the call, or your phone was off.
Can I block calls from a specific area code or country?
Your phone's built-in blocking usually works only for specific numbers, not patterns. Your carrier's blocking service (Verizon Call Filter, AT&T Call Protect, T-Mobile Scam Shield) may offer regional blocking. Third-party apps like TrueCaller and RoboKiller can block entire countries or area codes, though this requires their paid plans.
What if I block a number by mistake?
Unblock it when ready using the same method you used to block it. On iPhone, go to Settings > Phone > Manage Blocked Contacts. On Android, go to Phone app > Settings > Blocked Numbers. Find the number and tap Unblock. The person can then call or text you normally again.
Do I need to block a number on both my phone and my carrier?
No. Blocking on your phone is usually enough. If you also block through your carrier, you have two layers of protection, but one is sufficient. Carrier blocking can be useful if you want the same block list on multiple phones or if your phone's blocking is not working well.