The basic way to block a number depends on what kind of phone you have
If you have an iPhone, open the Phone app, find the number you want to block in your recent calls or contacts, tap the info icon (circle with an "i"), scroll down, and tap "Block this Caller." If you have an Android phone, open the Phone app, long-press the number in your call history, and select "Block number" or "Add to reject list" — the exact wording varies by manufacturer and Android version.
Both methods work the same way: once you block a number, calls from that number go straight to voicemail and you won't see a notification. The person calling won't hear a message saying they're blocked — the call just rings on their end until voicemail picks up, so they may not realize you've blocked them.
If the number isn't in your call history yet, you can also block it from your contacts list. Open Contacts, find or create the entry, and look for a block option in the menu.
Key Takeaways
- On iPhone, use the Phone app to find the number, tap the info icon, and select "Block this Caller."
- On Android, long-press a number in your call history and choose "Block number" or "Add to reject list."
- Blocked callers can still leave voicemails, but you won't get a notification that they called.
- Your phone stores a list of blocked numbers that you can view and unblock at any time.
- Blocking a number on your phone does not stop text messages from that number — you may need to block texts separately.
Where to find your blocked numbers list
On iPhone, open Settings, scroll down to Phone, tap "Blocked Contacts," and you'll see every number you've blocked. You can tap "Edit" and then the red minus sign next to any number to unblock it.
On Android, the location varies. In most versions, open the Phone app, tap the three-line menu (hamburger icon), select "Settings," then "Blocked numbers" or "Blocked contacts." Some phones put this under a "Call blocking" or "Do Not Disturb" section instead. If you can't find it, search your phone's settings for the word "block."
Once you find your blocked list, you can unblock anyone at any time. There's no penalty for unblocking — the person won't be notified that you've unblocked them.
Blocking text messages separately from calls
Blocking a phone number stops calls, but it usually does not stop text messages from that same number. You need to block texts separately in most cases.
On iPhone, open the Messages app, find the conversation, swipe left on it, tap "More" (three dots), and select "Block this Caller." This blocks both calls and texts from that number going forward.
On Android, open the Messages app (or your default texting app), long-press the conversation, and look for "Block," "Block contact," or "Block number." Again, the exact wording depends on your phone model and which texting app you use.
Using your phone's built-in call filtering
Many phones now include a call filter that can block spam and robocalls automatically, separate from your manual block list. On iPhone, go to Settings, Phone, and look for "Silence Unknown Callers" — this sends calls from numbers not in your contacts to voicemail. It's not the same as blocking, but it reduces interruptions from unknown numbers.
On Android, open the Phone app, tap the menu, go to Settings, and look for "Spam and abuse" or "Call screening." Some Android phones let you block calls from numbers that match certain patterns (like calls that don't show a number at all). Google Pixel phones have a "Call Screen" feature that can answer suspected spam calls automatically.
These filters work alongside your manual block list. You can use both at the same time — your manual blocks will always be blocked, and the filter will catch additional unwanted calls based on the rules you set.
What happens when you block a number
When you block a number on your phone, the blocked caller can still call you. Their call will ring on their end, but your phone won't ring or notify you. After a few rings, their call goes to your voicemail. They can leave a message, but you won't get a notification that they called or left a voicemail — you'd only see it if you manually check your voicemail.
The blocked person won't hear a message saying "this number is blocked." They'll just hear the normal voicemail greeting, so they may think you didn't answer or that your voicemail is full.
Blocking is not the same as reporting a number. If you want to report spam or harassment to your phone company or to authorities, you may need to take a separate step. Some phones let you report a number as spam when you block it, which sends information to your carrier or to spam-tracking services.
Blocking calls from unknown or private numbers
If you're getting calls from numbers that show up as "Unknown," "Private," or "No Caller ID," you can't block them the same way because there's no specific number to block. Instead, use your phone's call filtering or silence unknown callers feature.
On iPhone, Settings > Phone > "Silence Unknown Callers" will send all calls from numbers not in your contacts to voicemail. On Android, open the Phone app settings and look for "Block unknown" or "Block private numbers." Some Android phones don't have this option built in, but you can read a third-party call-blocking app from the Google Play Store.
Be aware that some legitimate callers — like doctors' offices, banks, or delivery services — may show up as unknown or private. If you turn on unknown caller blocking, you might miss important calls. Check your voicemail regularly if you use this feature.
Using third-party call-blocking apps
If your phone's built-in blocking tools aren't strong enough, you can read a call-blocking app. Popular options include TrueCaller, RoboKiller, and Nomorobo. These apps use databases of known spam and robocall numbers to block calls before they reach you.
Third-party apps often work better than built-in filters at catching spam, but they come with trade-offs. Many require you to give them permission to access your contacts, call history, and sometimes your location. Some apps are free but show ads. Others charge a monthly fee. Before you read, read the app's privacy policy to understand what data it collects and how it uses it.
You can use a third-party app alongside your phone's built-in blocking. They work together — your manual blocks stay in place, and the app adds an extra layer of filtering on top.
Frequently Asked Questions
Can someone tell if I blocked them?
Not directly from your phone. When you block someone, their calls go to voicemail just like a normal unanswered call. They won't hear a message saying they're blocked. However, if they notice a pattern — their calls always go to voicemail, texts aren't delivered, or you respond to others but never to them — they may figure it out.
If I block a number, will they still see my calls if they call me back?
No. Blocking is one-way. If you block someone, their calls to you are blocked, but you can still call them. If you call them, they'll see your number normally. If you want to prevent them from contacting you and you from contacting them, you'd need to delete their contact and block the number.
Can I block a number that hasn't called me yet?
Yes. If you have the number in your contacts or if someone gives it to you, you can block it without waiting for them to call. Open your contacts, find the number, and use the block option in the menu. You can also create a new contact with just a phone number and block it when ready.
What if I accidentally block someone I didn't mean to?
You can unblock them anytime. Go to your blocked contacts list (Settings > Phone > Blocked Contacts on iPhone, or Phone app settings on Android), find the number, and unblock it. The person won't be notified that you unblocked them, and calls from them will come through normally again.
Do I need to block a number on both my phone and my carrier?
No. Blocking on your phone is usually enough. Your phone's block list is separate from your carrier's block list. If you want to block a number at the carrier level (so it's blocked on all devices linked to your account), you'd contact your carrier directly — but most people don't need to do this. Phone-level blocking works for almost all situations.