The fastest way to block robocalls depends on your phone type

Most phones now have built-in robocall blocking that works without downloading anything. On an iPhone, open Settings, tap Phone, then Call Blocking & Identification, and turn on "Filter Unknown Callers" — this sends calls from numbers not in your contacts to voicemail. On Android, open the Phone app, tap the three-line menu, go to Settings, then Spam and Abuse, and turn on "Filter Spam Calls." Both methods work immediately and catch most robocalls automatically.

If your phone's built-in filter isn't catching enough calls, or if you want more control over what gets blocked, your phone carrier offers a second layer. Call your carrier's customer service line (the number on your bill) and ask them to turn on their robocall-blocking service — AT&T Call Protect, Verizon Call Filter, T-Mobile Scam Shield, or your carrier's equivalent. These services are often free and block calls before they reach your phone. Some carriers charge a small monthly fee for the premium version, which adds extra features like reverse lookup and spam reporting.

Key Takeaways

  • Your phone's built-in settings (Filter Unknown Callers on iPhone, Filter Spam Calls on Android) block most robocalls without any extra steps or cost.
  • Your phone carrier offers a second layer of blocking through services like AT&T Call Protect or Verizon Call Filter, which you can turn on by calling customer service.
  • Third-party apps like RoboKiller and Nomorobo add extra blocking features, but you should only download them from your phone's official app store.
  • Never answer calls from unknown numbers, never press buttons when a robocall asks you to, and never give out personal information — these actions teach robocallers your number is active.
  • If a robocall claims to be from your bank or the IRS, hang up and call the official number on your statement or the agency's website instead.

How to set up blocking on iPhone

Open Settings on your home screen. Scroll down and tap Phone. Tap Call Blocking & Identification. You will see three options: Filter Unknown Callers, Silence Unknown Callers, and Blocked Contacts. Turn on "Filter Unknown Callers" — this sends any call from a number not in your contacts, favorites, or recent calls to voicemail. The caller will not hear a busy signal; the call simply goes to voicemail as if you were unavailable.

If you want to block a specific number that keeps calling you, tap Blocked Contacts and add the number manually. You can also block a number right after a call ends by tapping the "i" icon next to the number in your recent calls list, scrolling down, and tapping "Block this Caller." Once blocked, that number cannot reach you by call or text.

How to set up blocking on Android

Open the Phone app (the one you use to make calls). Tap the three horizontal lines in the top-left corner to open the menu. Tap Settings. Tap Spam and Abuse. Turn on "Filter Spam Calls." This setting varies slightly by phone manufacturer and carrier, but the option is usually in the same location. Once turned on, suspected spam calls will be blocked automatically.

To block a specific number on Android, open the Phone app, find the number in your call history, press and hold it, and tap "Block number." You can also open the Contacts app, find the contact, tap the three dots, and select "Block contact." Like iPhone, blocked numbers cannot call or text you.

Adding your carrier's robocall filter

Your phone company has its own robocall-blocking service that works at the network level — meaning it stops calls before they even reach your phone. Call the customer service number on your phone bill and ask to turn on their spam-blocking service. AT&T offers Call Protect (free basic version), Verizon offers Call Filter (free basic version), T-Mobile offers Scam Shield (free basic version), and smaller carriers have similar services under different names.

The free versions of these services block most robocalls and are worth turning on even if your phone's built-in filter is already active — they catch different calls because they work differently. The premium versions (usually $3 to $5 per month) add features like reverse phone lookup, spam reporting, and the ability to see which calls were blocked. Ask your carrier which version is right for you, and whether they offer a free trial of the premium service.

Third-party blocking apps and when to use them

Apps like RoboKiller, Nomorobo, and Truecaller add extra blocking features beyond what your phone and carrier offer. RoboKiller uses artificial intelligence to learn which calls are spam and can even answer robocalls with a fake voicemail. Nomorobo maintains a crowdsourced list of known robocall numbers. Truecaller shows you the name and type of caller (spam, business, contact) before you answer. These apps are optional — your phone's built-in filter and carrier service catch most robocalls — but some people find the extra features worth the cost.

If you decide to download a third-party app, download it only from the official app store for your phone (Apple App Store for iPhone, Google Play for Android). Never download from a website or link in an email, even if it claims to be from your carrier. Check the app's reviews and permissions before installing — a legitimate blocking app should not ask for access to your photos, location, or email. Most third-party apps cost between $2 and $5 per month or offer a free version with limited features.

What to do if a robocall gets through

If a robocall reaches you despite your filters, do not answer if you do not recognize the number. If you do answer by accident, hang up immediately — do not press any buttons, even if the message says "press 1 to remove your number." Pressing buttons teaches robocallers that your number is active and monitored, which makes you a target for more calls. Robocallers use these button presses to verify numbers and sell them to other scammers.

If the call claims to be from your bank, the IRS, your utility company, or any official organization, hang up and call the official number from your statement or the organization's website. Robocallers often spoof real phone numbers to look legitimate. Real banks and government agencies do not call you out of the blue asking for personal information or payment. Report the call to the Federal Trade Commission at ReportFraud.ftc.gov or to your carrier's abuse team.

Why robocalls still get through sometimes

Robocallers spoof phone numbers — they make their call appear to come from a local number, a business you know, or even your own number. Your phone's filter cannot always tell the difference between a spoofed robocall and a real call from someone nearby. Carriers are working on a system called STIR/SHAKEN that verifies whether a call is really from the number it claims to be, but it is not yet available everywhere and not all carriers use it yet.

Some robocalls also use new numbers constantly, so they slip past filters that rely on known bad numbers. This is why layering your defenses — using your phone's built-in filter, your carrier's service, and your own judgment about answering unknown numbers — works better than any single method alone. No blocking system catches 100 percent of robocalls, but combining these methods will stop the vast majority.

Frequently Asked Questions

Will blocking robocalls stop me from getting calls I actually want?

No. Your phone's built-in filter only blocks calls from numbers not in your contacts or recent calls. If a business or person you know tries to call you, they will get through. If you miss a call from an unknown number that turns out to be important, they can leave a voicemail and you will see it in your voicemail list.

Can I block robocalls without paying anything?

Yes. Your phone's built-in filter (Filter Unknown Callers on iPhone, Filter Spam Calls on Android) is free and requires no setup beyond turning it on. Your carrier's basic robocall-blocking service is also free. You only pay if you want a third-party app or your carrier's premium version with extra features.

What if I keep getting calls from the same robocall number?

Block that specific number in your phone's settings. On iPhone, tap the "i" next to the number in your recent calls and select "Block this Caller." On Android, press and hold the number and tap "Block number." Once blocked, that number cannot reach you. Note that robocallers often use different numbers each time, so blocking one number may not stop the calls entirely — your carrier's filter is more effective against repeated robocalls.

Is it safe to download a third-party robocall-blocking app?

Download only from your phone's official app store (Apple App Store or Google Play). Check the app's reviews and permissions before installing — it should not ask for access to your photos, location, or email. Legitimate blocking apps are made by known companies like RoboKiller, Nomorobo, and Truecaller. If you are unsure about an app, stick with your phone's built-in filter and carrier service instead.

What should I do if a robocall claims to be from my bank?

Hang up immediately and call your bank using the number on your debit card or bank statement. Robocallers often spoof real bank numbers to trick you into giving out account information or passwords. Real banks do not call asking for personal details or payment over the phone. If you are concerned about your account, calling the official number is the only safe way to check.