The fastest way depends on what phone you have

Blocking a number takes less than a minute on any modern phone, but the steps differ between iPhone and Android. On an iPhone, you open the Phone app, find the number in your recent calls or contacts, tap the info icon, and select "Block this Caller." On Android, the process is similar: open the Phone app, long-press the number, and tap "Block number." Both phones also let you block a contact directly from your contacts list by opening their card and choosing the block option.

If you do not know the number or it is not in your phone yet, you can still block it after it calls or texts you. The blocked number will not be able to reach you by phone or text, though they may not know they are blocked — they will straightforward get a message that the call could not go through, which happens for many reasons.

Key Takeaways

  • iPhone users block numbers through the Phone app by tapping the info icon next to a recent call, then selecting "Block this Caller."
  • Android users long-press a number in the Phone app and tap "Block number" from the menu that appears.
  • Blocked numbers cannot call or text you, but they will not receive a notification that they are blocked.
  • You can unblock a number at any time by going to your phone's settings and finding the blocked contacts list.
  • Third-party apps like Nomorobo or Truecaller can block numbers automatically based on spam databases, though they require separate setup.

Blocking on iPhone step by step

Open the Phone app and go to the Recents tab at the bottom. Find the number you want to block in the list of recent calls. Tap the small circle with an "i" next to the number — this opens the caller details. Scroll down and tap "Block this Caller," then confirm by tapping "Block Contact" in the popup that appears.

If the number is already in your Contacts app, you can block it from there instead. Open Contacts, find the person's name, tap "Edit" in the top right, scroll to the bottom, and tap "Block this Caller." You can also block a number while you are on a call with them by tapping the red phone icon to end the call, then following the steps above.

To see all your blocked numbers on iPhone, go to Settings, tap Phone, scroll down to "Blocked Contacts," and tap "Edit" to add or remove numbers. You can also unblock someone by tapping the minus sign next to their name.

Blocking on Android step by step

Open the Phone app and go to the Recents tab. Long-press (hold your finger on) the number you want to block until a menu appears. Tap "Block number" or "Block contact" — the exact wording depends on your phone's manufacturer, but it will be clearly labeled. A confirmation message will appear; tap "Block" or "OK" to finish.

If the number is in your Contacts, you can block it from there as well. Open Contacts, find the person, tap the three-dot menu icon at the top right, and select "Block number." Some Android phones also let you block a number while on a call by tapping the three-dot menu during the call and selecting "Block."

To view your blocked numbers on Android, open the Phone app, tap the three-dot menu, go to Settings, and look for "Blocked numbers" or "Blocked contacts." The exact location varies by manufacturer — Samsung phones put it under "More settings," while Google Pixel phones put it directly in the Phone app settings. You can unblock a number by opening this list and tapping the minus or delete icon next to the contact.

What happens when you block a number

When you block a number, that person can no longer call you, send you text messages, or reach you through FaceTime or iMessage if you are on iPhone. On Android, they cannot call or text you, though some messaging apps like WhatsApp or Facebook Messenger may still work if you have not blocked them there separately.

The blocked person will not see a message saying "you are blocked." Instead, their call will go to voicemail (if you have voicemail set up) or they will hear a message that the call could not go through. A text message they send will appear to send normally on their end, but you will never receive it. This means they may not realize they are blocked — they might think your phone is off or you are ignoring them.

Blocking is not the same as reporting spam. If you want to report a number to your phone carrier or to the Federal Trade Commission, you will need to take a separate step. Most phones have a "Report as Spam" option alongside the block option, which sends information about the number to your carrier's spam database.

Using third-party apps to block numbers automatically

If you receive many spam or unwanted calls, a third-party blocking app can filter them before they reach you. Apps like Nomorobo, Truecaller, and RoboKiller use databases of known spam numbers to block calls automatically. You read the app, give it permission to access your phone calls, and it blocks numbers on that list without you having to do anything.

These apps work differently on iPhone and Android. On iPhone, they use a feature called Call Filter that intercepts calls before they ring. On Android, they typically replace your default Phone app or work alongside it. Some apps are free with limited features, while others charge a monthly fee for more advanced filtering.

The trade-off is that these apps see information about every call you receive in order to check it against their spam database. If privacy is a concern, read the app's privacy policy before installing it. You can also block numbers manually without using an app — it takes longer if you get many spam calls, but you maintain more control over what information leaves your phone.

Blocking numbers from unknown callers and private numbers

If you receive calls from numbers that show up as "Unknown," "Private," or "Blocked," you cannot block them the same way because there is no actual number to block. Instead, you can silence calls from unknown numbers. On iPhone, go to Settings, tap Phone, and turn on "Silence Unknown Callers" — this sends calls from numbers not in your contacts to voicemail. On Android, open the Phone app, tap the three-dot menu, go to Settings, and look for "Block unknown" or "Unknown caller rejection."

This approach blocks all calls from numbers not in your contacts, which means you might miss important calls from your doctor, your bank, or a business you are expecting to hear from. A middle ground is to let calls ring but enable Do Not Disturb mode, which silences notifications but still lets calls from your contacts get through. You can set this up in your phone's settings to turn on automatically at certain times of day.

Unblocking a number if you change your mind

You can unblock a number at any time. On iPhone, go to Settings, tap Phone, tap "Blocked Contacts," and swipe left on the contact you want to unblock, then tap "Unblock." On Android, open the Phone app, tap the three-dot menu, go to Settings, find "Blocked numbers," and tap the minus or delete icon next to the contact.

Once you unblock a number, that person can call and text you again when ready. They will not be notified that you unblocked them. If you want to block them again in the future, you can do so using the same steps.

Frequently Asked Questions

Can someone tell if I blocked them?

No, there is no notification sent to them. Their calls will go to voicemail and texts will appear to send on their end, so they may not realize they are blocked. They might assume your phone is off, you are busy, or you are ignoring them.

What is the difference between blocking and reporting as spam?

Blocking stops that specific number from reaching you. Reporting as spam sends information about the number to your carrier or to spam databases so they can block it for other people too. You can do both at the same time on most phones.

If I block someone, can they still leave me a voicemail?

No. On both iPhone and Android, blocked callers cannot leave voicemail. Their call goes to voicemail, but the message is not saved or delivered to you.

Will blocking a number stop them from reaching me on social media or email?

No. Blocking a phone number only blocks calls and texts on your phone. If you want to block someone on Facebook, Instagram, email, or another platform, you need to block them separately in each app or service.

Can I block a number that texted me but never called?

Yes. On both iPhone and Android, you can block a number from your text message thread. Open the conversation, tap the contact name or number at the top, and look for a "Block" or "Block this Contact" option.