How to Block Unknown Calls on the iPhone

Receiving repeated calls from unknown callers is just plain irritating. The feature to block someone or block a number on your iPhone has been around for a while, but not until iOS 13 did we got a workaround to block private numbers where there is no caller ID. You might think calling from a hidden number would be illegal! The Federal Communications Commission, or FCC, actually mandates that phone companies make it freely available to block caller ID and keep your number private. Of course, the FCC also mandates that telemarketers are not allowed to hide their numbers. Still, without a way to trace a private call back to a particular company or person, this law is decidedly toothless. If the government isn't going to stop telemarketers, scammers, and other nuisance callers from hiding their numbers, then it is up to us to put an end to unwanted calls. Fortunately, you can easily block a number on your iPhone, block unknown callers, block no caller ID, and even stop calls from hidden numbers as well. Let's get started learning how to block nuisance calls on our iPhones.

Related: How to Check Voicemails from Blocked Numbers on iPhone

What's in This Article:

How to Block a Number on Your iPhone

To begin our journey of stopping nuisance calls, let's learn how to block a number. Remember, you can add your own phone number to the National Do Not Call registry. Once your number has been listed for 31 days, if you receive an unwanted call, you can report it. The offending company will receive a penalty. Not every nuisance caller is a telemarketer, though. Sometimes you get calls over and over again from the same number, so you might need to block a phone number just to keep yourself sane. Here's how to block someone on your iPhone:

  1. Open the Phone app.
  2. Tap Recents at the bottom of the screen.
  3. Find the number you want to block and tap the “i”.

  4. Scroll down to the bottom of the screen and tap Block This Caller.

Return to top.​​ ​​

How to Silence Unknown Callers and Those with No Caller ID

This feature, introduced with iOS 13, will block unknown calls by sending all calls from unknown numbers straight to voicemail. If you don't have iOS 13 then skip down to the next section for an alternative method. With this feature you could miss important calls from numbers that you haven't listed in your Contacts, like your doctor or pharmacy. However, it's very useful for weeding out robo-calls, scammers, spoofers, and telemarketers. This method also silences phone calls made using this common trick to hide your Caller ID, even those made by people in your Contact's list. Here's how to enable Silence Unknown Callers to block unknown calls on your iPhone:

  1. Open the Settings app.
  2. Select Phone.
  3. Toggle Silence Unknown Callers to on.

You've done it! Enjoy the sweet, sweet silence. But remember that when your bank or doctor offers to call you back, you'll have to ask them what number they'll be calling from and make sure to add it to your contacts, or else you'll likely miss the call. There is a caveat to this approach: it doesn't silence calls from numbers which Siri identifies as suggested contacts. If a number repeatedly calls you, for example a political operative trying to talk up their candidate, then Siri may identify them as a possible friend, and then their calls will start getting through again. 

​​Return to top.​​

How to Block All Unknown Numbers Using Do Not Disturb

If have an older version of the iOS, you can still block unknown callers. Simply set Do Not Disturb to a 24-hour schedule and allow calls only from your contacts. Keep in mind that if you receive an important call from someone who isn't in your contacts, you'll miss it. You can, however, check for voicemails even from blocked calls. There's also an option to allow a second call from the same person within three minutes to go through, so you can be reached in an emergency. Like the Silence Unknown Callers method, the Do Not Disturb method will block all calls labeled "No Caller ID," even if the call is being made by someone on contact's list. Here’s how to block calls from all unknown numbers:

  1. Open Settings.
  2. Tap Do Not Disturb.
  3. Select Allow Calls From.

  4. Select All Contacts.

  5. Return to previous menu and toggle on Scheduled.
  6. Set schedule to a 24-hour period.

Now, your Do Not Disturb function will automatically stay on and only calls from your contacts will make a sound.

Return to top.

How to Unblock a Number on Your iPhone

If you've gotten overzealous with your call blocking, don't worry, it happens. Here's how to unblock a number that you blocked.

  1. Open the Settings app.
  2. Tap Phone.

  3. Tap Blocked Numbers, and you'll see a list of all the numbers you've blocked.
  4. Tap Edit in the top right corner.

  5. Tap the red circled minus sign to remove a number from the list.
  6. Tap Done to finish.

Return to top.​​

Use a Blocking App to Stop Nuisance & Anonymous Calls 

If your phone company can't offer you a way to stop nuisance calls, there are several third-party apps that can help. Here are two of my top picks.



RoboKiller is an app is designed to identify robocalls and spam, as well as unmasking unknown numbers with "Super Caller ID." Winning the FTC's anti-robocall competition gives RoboKiller a lot of credibility as one of the best nuisance blockers out there. RoboKiller's developers offer a one-week free trial, followed by a monthly charge. If you're enthusiastic about RoboKiller and find it's the solution you've been looking for, you can purchase a one-year membership for $29.99.

Hiya Caller ID and Block

Hiya is a call-blocking, spam-filtering app that reveals the phone numbers of blocked callers, uses a call protection database to safeguard customers, and allows individuals to customize their own block list. Named a Time Magazine Top Ten App, Hiya is free, and can even be shared by up to six people on a Family Sharing plan.

How to Enable a Call Detector App on Your iPhone

If you decide to install a third-party app to filter out unwanted calls, you'll need to change a few settings to get started.

  1. Open the Settings app.
  2. Scroll down to Phone and tap on it.
  3. Tap on Call Blocking & Identification. Note that this option only appears once a call blocking app is downloaded and installed from the App Store, as above.

  4. Under Allow These Apps To Block Calls And Provide Caller ID, turn your call-blocking app on. ​​

I hope this article has helped to solve your problem with nuisance calls to your iPhone. While these methods won't block Emergency Alerts on the iPhone, taking these steps will definitely reduce the daily interruptions. Please let me know what worked best for you, and if you have any favorite spam-blocking apps in the comments.

Top Image Credit: Denys Prykhodov /
Master your iPhone in one minute a day: Sign up here to get our FREE Tip of the Day delivered right to your inbox.


Author Details

Cullen Thomas's picture

Author Details

Cullen Thomas

Cullen Thomas is a Writer and Producer at iPhone Life, creating tips and guides to help users unlock the full potential of their iOS and iPhone. In addition to writing countless tip-of-the-day articles and many detailed guides, Cullen has spent nine years as an instructor in media and communications at Maharishi University, lecturing on technical and artistic subjects ranging from camera and audio hardware to story-plotting to how to manage a film crew. Cullen answers questions daily about iPhones and iOS as part of the Ask an Editor insider service, and designs curriculum for iPhone Life’s online classes. As a frequent contributor to iPhone Life magazine and occasional guest on the iPhone Life podcast, Cullen likes to talk about security and privacy news, tech, gadgets, and apps, even if nobody asked.

Cullen holds a master’s degree in Cinematic Arts from the David Lynch School of Cinematic Arts. Cullen also holds two Bachelor’s degrees from Maharishi University, one in literature with an emphasis in writing and the other in Communications and Media. Cullen’s short fiction has been featured in anthologies from Amphibian Press and TANSTAAFL, and Cullen co-owns a game design company, Thoughtspike games, which builds thought-provoking puzzle games. Cullen is a sci-fi author, a coffee connoisseur, and an iPhone expert.