The fastest way depends on your phone type

On most phones, you can block a call in real time while it's ringing, or block the number afterward. If the call is coming in right now, look for a "Decline" or "Reject" button on your screen and tap it — that stops the call without answering. If you want to block that number from calling again, you'll find the block option in your recent calls list or in your phone's settings.

The exact steps differ between iPhones and Android phones, and some carriers offer their own blocking tools on top of what your phone provides. This guide covers the main methods for each type of device.

Key Takeaways

  • You can reject a call while it's ringing by tapping "Decline" or "Reject" on your screen, then block the number afterward from your call history.
  • On iPhone, open the Phone app, find the number in Recents, swipe left, and tap "Block this Caller" — or go to Settings > Phone > Blocked Contacts to manage your list.
  • On Android, open the Phone app, long-press the number in your call history, and select "Block number" — the exact wording varies by manufacturer.
  • Your carrier may offer a separate blocking service (AT&T Call Protect, T-Mobile Scam Shield, Verizon Call Filter) that works alongside your phone's built-in tools.
  • Blocked numbers can still leave voicemails on most phones unless you turn off that feature in your voicemail settings.

Blocking a call on iPhone

Open the Phone app and tap the "Recents" tab at the bottom. Find the number you want to block, then swipe left across it. A red "Block this Caller" button will appear — tap it. The number is now blocked, and calls from it will go straight to voicemail.

If you want to see or manage your full list of blocked numbers, go to Settings > Phone > Blocked Contacts. You can unblock a number by tapping "Edit" and then the minus sign next to the number, or by swiping left and tapping "Unblock."

You can also block a number directly from a call. While the call is ringing, tap "Decline," then tap the small "i" icon next to the number. Scroll down and tap "Block this Caller."

Blocking a call on Android

Open the Phone app (the one you use to make calls, not your contacts app). Go to the "Recents" or "Call History" tab. Long-press the number you want to block — hold your finger on it for a second or two until a menu appears. Select "Block number" or "Block contact." The exact wording depends on your phone's manufacturer and Android version.

To see your blocked numbers, open the Phone app and look for a menu icon (three dots or lines) in the top corner. Tap it and select "Settings," then look for "Blocked numbers" or "Block list." You can unblock a number by tapping it and selecting "Unblock."

Some Android phones let you block a number while the call is ringing. Look for a "Decline" or "Reject" button, tap it, then immediately tap "Block" or "Block number" when prompted.

Using your carrier's blocking service

Your phone company may offer its own call-blocking tool that works separately from your phone's built-in features. These services filter calls before they reach your phone and often catch spam and scam calls your phone alone might miss.

AT&T offers AT&T Call Protect, which blocks known spam numbers automatically. You can manage it through the AT&T Mobile app or by calling 611 from your AT&T phone. T-Mobile includes Scam Shield, which you can turn on in the T-Mobile app or by dialing #662# from your phone. Verizon offers Call Filter, available through the My Verizon app or by calling 611.

These services are often free at a basic level, though some carriers charge a small monthly fee for advanced features like caller ID and spam detection. Check your carrier's website or call customer service to see what's included with your plan.

What happens when you block a number

When you block a number, calls from that number will no longer ring your phone. Instead, they go directly to voicemail. The caller won't hear a message saying they're blocked — the call will just ring once or twice and then go to voicemail, so they may not realize you've blocked them.

Text messages from a blocked number also won't reach you on most phones. However, blocked callers can still leave voicemails unless you disable that feature. If you want to prevent voicemails from blocked numbers, go to your voicemail settings and look for an option to reject voicemails from blocked contacts.

You can unblock a number at any time using the same steps you used to block it. There's no limit to how many numbers you can block.

When blocking isn't enough

If you're getting repeated calls from different numbers or from callers who spoof their number (make it appear as something it isn't), blocking individual numbers won't solve the problem. In that case, your carrier's spam filter or a third-party app may help more than manual blocking.

If you're being harassed or threatened, contact your local police and ask about filing a report. You can also report spam and scam calls to the Federal Trade Commission at reportfraud.ftc.gov. Some carriers will work with law enforcement if there's an active investigation.

Frequently Asked Questions

Can someone tell if I've blocked them?

Not directly. When a blocked caller tries to reach you, the call goes to voicemail without ringing your phone. They won't hear a message saying they're blocked, so they may assume you're busy or didn't answer. Over time, if they notice calls always go to voicemail, they might suspect you've blocked them, but there's no way for them to know for certain.

Will blocked numbers still be able to text me?

No. On most phones, text messages from blocked numbers won't reach your inbox. However, some older phones or certain messaging apps may handle this differently, so check your settings if you're unsure. You can usually see blocked messages in a separate folder or not at all, depending on your phone.

What if the same person keeps calling from different numbers?

Block each number as it appears. If the harassment continues, take screenshots of the calls and texts, then report it to your carrier and local police. Your carrier may be able to see a pattern and block the source more broadly, especially if it's a spoofing operation.

Can I block calls from unknown numbers?

Most phones don't let you block all unknown numbers at once, but your carrier's spam filter can catch many of them automatically. On iPhone, you can enable "Silence Unknown Callers" in Settings > Phone, which sends calls from numbers not in your contacts to voicemail. Android phones have similar options under "Block unknown" or "Filter unknown calls" in the Phone app settings.

Do I need to pay for call blocking?

Your phone's built-in blocking is free. Your carrier's basic spam filter is usually free too, though some carriers charge for advanced features. Third-party blocking apps are available on both iPhone and Android, with free and paid versions. You don't need to pay anything to block a specific number.