The fastest way depends on your phone type
On most phones, you can block a number directly from the call log or contacts app in under a minute. iPhone users open the Phone app, find the number in Recent calls, tap the info icon, and select "Block this Caller." Android users open the Phone app, long-press the number in the call log, and tap "Block number" — the exact wording varies by manufacturer and Android version, but the option appears in a menu when you hold down the contact.
If you want to block before the person calls, you can add them to your contacts first, then use the same blocking steps. Some phones also let you block directly from a text message by tapping and holding the conversation, though blocking via the Phone app works more reliably across all devices.
The blocked number will not reach you by call or text, and they will not receive a notification that they are blocked — the call or message will simply fail on their end. You can unblock the same way: find the number in your blocked list (usually in Phone settings) and select "Unblock."
Key Takeaways
- On iPhone, open the Phone app, tap the info icon next to a recent call, and select "Block this Caller."
- On Android, long-press a number in the call log and tap "Block number" — the exact menu name depends on your phone maker.
- Blocked numbers cannot reach you by call or text, and they receive no notification that they are blocked.
- You can unblock a number anytime through your phone's blocked contacts list in settings.
- Third-party call-blocking apps offer more filtering options but require separate setup and permissions.
Where to find your blocked list on each phone type
On iPhone, go to Settings > Phone > Blocked Contacts. This list shows every number you have blocked and lets you unblock any of them by swiping left and tapping "Unblock." You can also block a contact from this screen by tapping "Edit" and then the plus sign to add a new number manually.
On Android, the blocked list location varies. Most phones keep it in Phone app settings — open Phone, tap the three-line menu, go to Settings, then look for "Blocked numbers" or "Block list." Samsung phones put it under Phone > More options > Settings > Reject calls. Google Pixel phones use Phone > Settings > Blocked numbers. If you cannot find it in the Phone app, check your Messages app settings, as some Android versions let you block from there instead.
Once you find your blocked list, you can add numbers manually without waiting for them to call. This is useful if you know a number you want to block in advance — you simply type it in rather than waiting for the call to come through.
What happens when you block a number
A blocked caller will not hear a message saying they are blocked. Instead, their call goes to voicemail (if you have voicemail set up) or fails silently. Text messages from blocked numbers are usually hidden from your main message thread, though some phones move them to a separate folder you can view if needed.
The blocked person does not receive a notification, a busy signal, or any indication that the block is in place. From their perspective, the call or text simply did not go through — they may assume your phone is off, you are out of range, or your voicemail is full. This is by design: blocking is meant to stop unwanted contact without creating conflict.
Blocking is not the same as deleting. The number remains in your phone's memory, and you can unblock it at any time. Unblocking takes effect immediately, and the person can reach you again on their next attempt.
Using third-party call-blocking apps for more control
Your phone's built-in blocking works for numbers you already know about, but third-party apps can filter calls before they reach you. Apps like TrueCaller, RoboKiller, and Nomorobo maintain databases of known spam and scam numbers, and they can block entire categories of calls — telemarketing, robocalls, suspected fraud — without you having to block each number individually.
These apps require you to grant them permission to access your call log and contacts, and some require a subscription for full features. TrueCaller's free version blocks spam calls and shows caller ID for unknown numbers. RoboKiller's free tier blocks robocalls; the paid version adds call recording and advanced filtering. Nomorobo is free and focuses on blocking robocalls and spam.
The trade-off is that third-party apps use more battery and storage than your phone's built-in blocking, and they may not work as smoothly with your phone's native call screen. If you receive only occasional unwanted calls, your phone's native blocking is usually enough. If you get frequent spam or robocalls, a third-party app may reduce the noise significantly.
Blocking numbers from text messages and other apps
Text message blocking works the same way as call blocking on most phones. On iPhone, open the conversation, tap the contact name at the top, scroll down, and tap "Block this Caller." On Android, long-press the conversation in your Messages app and tap "Block" or "Block number."
For messaging apps like WhatsApp, Facebook Messenger, or iMessage, blocking usually happens within the app itself rather than at the phone level. Open the conversation, tap the contact name or info button, and look for a "Block" or "Report" option. Blocking in the app prevents that person from messaging you through that app only — they can still call or text your phone number unless you block them there too.
If someone is harassing you across multiple apps, you may need to block them in each one separately. Some phones also let you block at the contact level — if you block a contact in your address book, it can block them across calls, texts, and sometimes app notifications, depending on your phone's settings.
Dealing with spam and robocalls
Spam and robocalls are harder to block one at a time because the number often changes with each call. Your phone's native call-blocking tools work best when you block specific numbers you recognize. For widespread spam, your phone's built-in spam filter is usually the first line of defense.
On iPhone, go to Settings > Phone > Silence Unknown Callers to send calls from numbers not in your contacts to voicemail. This does not block them, but it stops them from ringing through. On Android, the Phone app usually has a spam filter toggle in settings — turn it on to automatically block calls flagged as spam by Google or your carrier.
If spam persists, contact your phone carrier. Most carriers offer free spam-blocking tools — AT&T Call Protect, Verizon Call Filter, and T-Mobile Scam Shield are built into their networks and can block entire categories of spam calls. You may need to turn them on in your carrier's app or account settings.
Frequently Asked Questions
Can a blocked person see that they are blocked?
No. A blocked caller will not receive a message, busy signal, or any notification. Their call goes to voicemail or fails silently. They may suspect they are blocked if calls consistently fail, but your phone does not tell them.
What if I block someone by accident?
You can unblock them immediately. On iPhone, go to Settings > Phone > Blocked Contacts, find the number, and tap "Edit" then the minus sign. On Android, open your blocked list in the Phone app settings, find the number, and tap "Unblock." They can reach you again on their next attempt.
Does blocking stop someone from seeing my location or social media?
No. Blocking only stops calls and texts. It does not affect location sharing, social media visibility, or other apps. You would need to block them separately in each app or adjust privacy settings there.
Can I block a number without adding it to my contacts first?
Yes. You can block a number directly from your call log or by typing it into your blocked list in settings. You do not need to create a contact first.
Will blocking someone stop them from leaving voicemails?
Blocking stops the call from reaching you, so it goes to voicemail. Whether they can leave a message depends on your voicemail settings. Some phones let you block voicemails from specific numbers separately, usually in voicemail settings.