The fastest way to block a call depends on your phone type
On most phones, you can block a number right from the call screen while it is ringing or when ready after. iPhone users swipe up on the incoming call and tap "Block this Caller." Android users tap the three-dot menu during or after the call and select "Block number." Both methods take three seconds and stop that number from calling or texting you again.
If you did not block during the call, you can block from your recent calls list. Open Phone or Recents, find the number, and look for a block or info option. The exact wording and location differ between phones, but every modern phone has this feature built in — you do not need an app.
Blocked callers will not hear a busy signal or a message saying they are blocked. Their call straightforward fails to ring through to you, and they may see a generic "call failed" message on their end. Text messages from blocked numbers are also silenced.
Key Takeaways
- You can block a number directly from an incoming call or from your recent calls list without downloading anything.
- iPhone and Android both have built-in blocking; the blocked caller will not know they are blocked.
- Blocked numbers cannot reach you by call or text, but you can unblock them later if you change your mind.
- If blocking individual numbers becomes tedious, your phone's settings menu has options to filter unknown callers automatically.
- Some carriers offer additional blocking tools through their own apps or websites, separate from your phone's built-in features.
Where to find the block option on iPhone
On iPhone, the block option appears in two places: during an active call and in your Phone app. If someone is calling you right now, swipe up from the bottom of the screen to reveal the keypad and other options, then tap "Block this Caller" at the bottom. The call will end when ready.
If you missed the call or want to block someone who texted you, open the Phone app and go to Recents. Find the number or contact, swipe left on it, and tap the trash icon, then "Block this Caller." You can also tap the "i" information icon next to a number, scroll down, and tap "Block this Caller." All three routes do the same thing.
To see your list of blocked contacts, open Settings, tap Phone, and select "Blocked Contacts." From here you can unblock anyone by tapping "Edit" and then the minus sign next to their name.
Where to find the block option on Android
Android phones vary by manufacturer, but the block option is always in or near your Phone app. During an incoming call, look for a three-dot menu icon at the top or bottom of the screen. Tap it and select "Block number" or "Block caller." After the call ends, open your Phone app, find the number in Recents or Call History, press and hold it, and tap "Block number."
Some Android phones also let you block directly from the contact card. Open Contacts, find the person, tap the three-dot menu, and choose "Block." Samsung phones have a dedicated "Block" button in the contact details. Google Pixel phones show the block option in the Phone app's recent calls list.
To manage your blocked list on Android, open Phone settings (usually found by tapping the three-dot menu in the Phone app itself), look for "Blocked numbers" or "Block list," and you will see everyone you have blocked. Tap any entry to unblock them.
Using your phone's automatic filtering for unknown numbers
If you are tired of blocking numbers one at a time, both iPhone and Android let you silence calls from people not in your contacts. On iPhone, go to Settings, tap Phone, and turn on "Silence Unknown Callers." Unknown numbers will still reach your voicemail, but they will not ring through or light up your screen.
Android offers a similar feature called "Filter Unknown Senders" or "Block Unknown" depending on your phone. Open Phone settings, find the spam or blocking section, and enable it. Google Pixel phones have this built into the Phone app itself — tap the three-dot menu, go to Settings, and toggle "Filter Unknown Calls."
These automatic filters are gentler than blocking specific numbers because they do not prevent calls entirely; they just silence them. You can still see that someone called and listen to their voicemail if they leave one. This is useful for reducing interruptions while keeping the option to return important calls you might have missed.
Blocking through your carrier's tools
Your phone company — Verizon, AT&T, T-Mobile, or another carrier — may offer its own blocking service separate from your phone's built-in features. These tools often catch spam and robocalls before they reach your phone at all, rather than just silencing them after they arrive.
Verizon offers Call Filter, which identifies spam calls and lets you block numbers through the Verizon app or website. AT&T has Call Protect, and T-Mobile has Scam Shield. Some of these services are free; others charge a small monthly fee for advanced features like blocking by category (debt collectors, telemarketers, etc.). You can turn them on through your carrier's app or by calling customer service.
Carrier-level blocking happens before the call reaches your phone, so you will not see it in your recent calls at all. This can be more effective than phone-level blocking for spam and robocalls, but it does not replace your phone's built-in block feature for numbers you personally want to avoid.
What happens when you block someone
When you block a number, that person cannot call you, text you, or reach you through FaceTime or iMessage (on iPhone). Their call will fail with a generic error message on their end — they will not hear a busy signal or a recording saying they are blocked. If they text you, the message will not appear on your phone, though they may not know it failed to deliver.
Blocked contacts cannot see that you have blocked them through your phone's behavior alone. However, if they try to call repeatedly and always get the same failure, they may suspect it. There is no notification that tells them "you have been blocked."
You can unblock someone at any time by going back to your blocked list and removing them. Once unblocked, they can call and text you normally again, and you will see their messages and calls as usual.
Blocking contacts you know versus unknown numbers
Blocking someone in your contacts works the same way as blocking an unknown number, but it also removes them from your contact list if you choose. On iPhone, when you block a contact, you have the option to "delete contact" at the same time. On Android, blocking and deleting are separate actions — you can block someone without removing them from your contacts.
If you block a contact without deleting them, you will still see their name and information in your Contacts app, but they cannot reach you. This is useful if you want to keep their information for reference but do not want them calling. If you delete the contact entirely, you lose their phone number unless you have it saved elsewhere.
For unknown numbers, there is no contact to delete — you are straightforward adding the number to your block list. If the same number calls again later with a different context (a wrong number that calls back to apologize, for example), you can unblock it quickly.
Frequently Asked Questions
Can a blocked person still leave me a voicemail?
On iPhone, blocked callers cannot leave voicemail — their call fails before reaching your voicemail system. On Android, it depends on your phone and carrier, but most Android phones also prevent blocked callers from leaving voicemail. If you want someone to be able to leave a message but not ring your phone, use the "Silence Unknown Callers" feature instead of blocking.
Will a blocked person know I blocked them?
No notification tells them they are blocked. Their call will straightforward fail with a generic error. However, if they call multiple times and always get the same failure, they may suspect blocking. There is no way for them to confirm it from their phone.
Can I block a number that is not in my contacts?
Yes. You can block any number that calls or texts you, whether or not you have saved it as a contact. Find it in your recent calls or messages, and use the block option. The number will be added to your block list even if you have never spoken to that person.
What if I accidentally block someone I want to hear from?
Open your blocked list in Phone settings and unblock them. On iPhone, go to Settings > Phone > Blocked Contacts and tap Edit, then the minus sign next to their name. On Android, open Phone settings, find Blocked Numbers, and tap the entry to unblock. Once unblocked, they can call and text you normally again.
Do I need an app to block calls?
No. Every modern iPhone and Android phone has blocking built in. You do not need to read anything. Your carrier may offer additional apps with extra features like spam detection, but basic blocking is always free and built into your phone.