Yes, you can block most spam calls with built-in phone tools or third-party apps

Every phone — whether iPhone, Android, or landline — has a way to block unwanted numbers. The simplest method is to block individual callers after they call you. Most phones also let you filter entire categories of calls (like unknown numbers or suspected spam) before they reach you. Some carriers offer spam-blocking services you can turn on in your account settings. The combination that works best depends on how many spam calls you get and whether you need to receive calls from numbers not in your contacts.

You do not need to pay for spam blocking. Your phone's built-in tools are free. Carrier services like AT&T Call Protect, Verizon Call Filter, and T-Mobile Scam Shield are free or low-cost. Third-party apps like Nomorobo, RoboKiller, and Truecaller add features beyond what your phone provides, but they are optional.

Key Takeaways

  • Every phone has a native block feature: on iPhone, open the call log, tap the number, and select "Block this Caller"; on Android, open the Phone app, find the number, and tap "Block".
  • Do Not Disturb mode (iPhone) and Do Not Disturb (Android) let you silence calls from unknown numbers while still ringing for contacts you have saved.
  • Your carrier offers spam filtering at no extra cost — check your account settings or call customer service to turn it on.
  • Third-party apps add features like call screening (hearing a message before you pick up) and machine learning that improves over time, but require you to grant them access to your call log.

Blocking individual numbers on your phone

The fastest way to stop a specific number is to block it directly from your phone's call history. On iPhone, open the Phone app, tap the "Recents" tab, find the number you want to block, tap the circle with an "i" next to it, scroll down, and tap "Block this Caller". On Android, open the Phone app, find the number in your call log, press and hold it, and tap "Block number" or the block icon (usually a circle with a slash).

Once you block a number, that caller cannot reach you by phone or FaceTime (iPhone) or by phone or Google Meet (Android). Their calls go straight to voicemail, and you will not see a notification. You can unblock the number the same way if you change your mind. Blocking one number at a time works if you get spam calls occasionally, but if you get many calls per day, you will want a broader filter.

Filtering unknown and suspected spam calls

Both iPhone and Android let you silence calls from numbers not in your contacts. On iPhone, go to Settings > Phone > Silence Unknown Callers. This sends any call from a number you have not saved to voicemail without ringing your phone. Your contacts will still ring through normally. On Android, open the Phone app, tap the three-line menu, go to Settings > Spam and Call Screen, and turn on "Filter spam calls" or "See caller ID and spam detection".

These built-in filters use your phone's own data — your contacts list and call history — to decide what to block. They do not learn from other users' reports the way third-party apps do. If you receive many calls from businesses or services you do not have saved (like delivery drivers, doctors' offices, or banks), this setting may block legitimate calls. You can check your voicemail to see what you missed and call back if needed.

Using your carrier's spam-blocking service

AT&T, Verizon, T-Mobile, and most other carriers offer spam filtering built into your account. These services use the carrier's network to identify spam patterns before calls reach your phone. AT&T Call Protect and Verizon Call Filter are free for most customers; T-Mobile Scam Shield is free for T-Mobile customers. You can turn these on through your carrier's app or website, or by calling customer service.

Carrier filtering works across your entire account, not just on one device. If you have multiple phones on the same plan, the filter applies to all of them. The downside is that carrier systems are less aggressive than third-party apps — they block only calls they are very confident are spam, so you may still receive some unwanted calls. Turning on your carrier's service is a good first step and costs nothing.

Third-party apps for advanced spam blocking

Nomorobo, RoboKiller, and Truecaller are the most widely used third-party spam blockers. These apps use machine learning and crowdsourced data from millions of users to identify spam patterns. They can block calls before your phone rings, show you the caller's name and reason for calling (if it is a known spam pattern), and even answer robocalls with a recorded message that makes the caller think you are not available.

Third-party apps require you to grant them access to your call log, contacts, and sometimes your location. Read the app's privacy policy before installing. Most offer a free version with basic blocking and a paid version with features like call recording or priority support. If you get many spam calls per day, a third-party app will reduce interruptions more than your phone's built-in tools alone.

What to do if spam calls continue

If you have turned on your phone's native filters, your carrier's spam service, and a third-party app and still receive spam calls, the calls may be coming from spoofed numbers — fake caller IDs that change with each call. Spoofed calls are harder to block because each one appears to come from a different number. In this case, do not answer calls from unknown numbers, and do not press any buttons or say anything if you do answer — this confirms your number is active and may increase spam.

You can report spam calls to the Federal Trade Commission (FTC) at ReportFraud.ftc.gov. If the calls are threatening or harassing, contact your local police department. If you are on the National Do Not Call Registry and still receive calls from telemarketers, you can file a complaint with the FTC as well. Reporting does not stop calls to your number when ready, but it helps law enforcement track patterns and shut down operations.

Landline spam blocking

If you have a traditional landline, your options depend on your phone service provider. Most landline providers (like Vonage, Ooma, or your local telephone company) offer spam filtering through their account settings or a separate app. Some require you to purchase a device like a CPF30 (a small box that connects to your phone line) or Nomorobo's landline service, which costs a few dollars per month.

Landline spam blocking is less sophisticated than mobile phone filtering because landlines do not have the same built-in software. If you receive many spam calls on a landline, a third-party device or service is usually necessary. Ask your provider what spam-blocking options are included in your plan before paying extra.

Frequently Asked Questions

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

On iPhone, blocked callers can still leave a voicemail, but you will not be notified and their message goes to a separate voicemail folder. On Android, behavior varies by phone and carrier — some allow voicemail from blocked numbers, others do not. Check your phone's settings or contact your carrier to confirm.

Will blocking a number let them know I blocked them?

No. When you block a number, the caller hears a message that their call could not go through, but they do not receive a notification that you specifically blocked them. They may assume your phone is off or you are not available.

Can I block calls from a specific area code?

Your phone's native blocking tools do not let you block entire area codes. Third-party apps like RoboKiller and Truecaller offer this feature. If most of your spam comes from one area code, a third-party app is worth trying.

What if I accidentally block a number I need?

You can unblock any number the same way you blocked it. On iPhone, go to Settings > Phone > Blocked Contacts and swipe left on the number to unblock. On Android, open the Phone app, go to Settings > Spam and Call Screen > Blocked numbers, and tap the number to unblock it.

Do I need to pay for spam blocking?

No. Your phone's built-in filters and your carrier's service are free. Third-party apps offer free versions with basic blocking and paid versions with extra features, but you can block spam without paying anything.