Your phone has built-in tools to stop most spam calls without extra apps

Every major phone — iPhone, Android, Samsung — includes a call-blocking feature you can turn on right now. These tools filter out known spam numbers automatically, and you can also manually block individual callers. The built-in options work for most people and cost nothing. If spam still gets through, a second layer of filtering from your carrier (Verizon, AT&T, T-Mobile, or others) can catch more.

The fastest route is to enable your phone's native spam filter, then add your carrier's service if needed. Both work in the background without you having to answer or do anything when a call comes in.

Key Takeaways

  • iPhone users can turn on "Filter Unknown Senders" in Settings > Phone to silence calls from numbers not in their contacts.
  • Android users can enable "Spam and Abuse" filtering in the Phone app settings, which blocks calls from known spam numbers.
  • You can manually block any single number by opening the call log, tapping the number, and selecting "Block this Caller."
  • Your carrier offers a second layer of spam filtering — Verizon Call Filter, AT&T Call Protect, and T-Mobile Scam Shield — which you can enable for free or a small monthly fee.
  • Do not answer calls from unknown numbers, and never give personal information to callers you did not initiate contact with.

How to block spam on iPhone

Open Settings, tap Phone, then scroll down and turn on "Filter Unknown Senders." This silences calls from numbers that are not in your contacts, your recent calls, or your message threads. The calls still come through — you can see them in the Phone app — but they do not ring or vibrate.

To block a specific number, open the Phone app, find the call in your recent list, tap the information icon (i) next to the number, scroll to the bottom, and tap "Block this Caller." That number will never ring through again. You can unblock it the same way if you change your mind.

If you want to report a number as spam to Apple, tap the same information icon and select "Report as Junk." Apple uses these reports to improve its filtering for all users.

How to block spam on Android

Open the Phone app, tap the three-line menu (hamburger icon) at the top, go to Settings, then Spam and Abuse. Turn on "Filter spam calls." Android will now block calls from numbers it recognizes as spam. Like iPhone, blocked calls appear in your call log but do not ring.

To block a single number, open the Phone app, find the call, press and hold it, then tap "Block number." You can also open a contact, tap the three dots at the top right, and select "Block number" from there.

If you want to report a number as spam, press and hold the call and tap "Report as spam." Google uses these reports to improve filtering across Android devices.

Adding your carrier's spam filter for extra protection

Your phone company — Verizon, AT&T, T-Mobile, or another carrier — offers its own spam-blocking service that works alongside your phone's built-in tools. These services catch spam that your phone's filter might miss because they have access to a larger database of known spam numbers.

Verizon Call Filter is free for most customers and blocks spam automatically. AT&T Call Protect has a free version that blocks known spam and a paid version ($3.99 per month) that adds more features. T-Mobile Scam Shield is free for T-Mobile customers. Check your carrier's website or call customer service to turn on whichever service applies to your account.

These services work in the background. Once enabled, you do not have to do anything — calls are filtered automatically.

Manually blocking numbers one at a time

If the same number keeps calling, block it directly. On iPhone, go to Phone > Recents, tap the information icon next to the number, and tap "Block this Caller." On Android, press and hold the number in your call log and tap "Block number."

Blocking a number prevents that caller from reaching you by phone or FaceTime (iPhone) or Google Meet (Android). They can still send text messages unless you block them separately in your Messages app. If you block a contact by mistake, you can unblock them the same way.

What to do if spam calls keep getting through

If you are still receiving spam calls after enabling your phone's filter and your carrier's service, the calls may be coming from spoofed numbers — fake caller IDs that change each time. These are harder to block because each call appears to come from a different number.

Do not answer calls from numbers you do not recognize. If you do answer by mistake, hang up when ready and do not press any buttons or say anything — spammers use responses to confirm your number is active. Never give personal information, passwords, or payment details to an unsolicited caller, even if they claim to be from your bank or the government.

If a number calls repeatedly, block it. If the calls are threatening or harassing, report them to the Federal Trade Commission at reportfraud.ftc.gov or contact your local police.

Why spam calls happen and how to reduce them

Spam calls come from scammers trying to steal money or personal information, telemarketers, and robocalls. Your number may have been sold to a list, posted online, or generated randomly by automated systems. Once a scammer confirms your number is real by getting you to answer, they may call more often.

To reduce spam, do not post your phone number publicly online, do not respond to texts asking you to confirm your number, and do not answer calls from unknown numbers. If you must give your number to a business, ask if they sell contact information to third parties. Some people use a separate phone number for online shopping or signups to keep their main number private.

Frequently Asked Questions

Will blocking a number let them know I blocked them?

No. When you block a number, the caller does not receive a notification. On iPhone, blocked callers hear a busy signal or the call goes to voicemail. On Android, the behavior depends on your carrier, but blocked callers typically cannot reach you.

Can I block all calls except my contacts?

Yes. On iPhone, turn on "Filter Unknown Senders" in Settings > Phone. On Android, enable "Filter spam calls" in the Phone app settings. Both options silence calls from numbers not in your contacts or recent history.

What if a legitimate business is blocked by mistake?

You can unblock the number. On iPhone, go to Settings > Phone > Blocked Contacts and swipe left on the number to unblock it. On Android, open Phone > Settings > Blocked numbers, find the number, and tap the X to unblock it. You can also check your voicemail to see if they left a message.

Do I need to pay for spam blocking?

No. Your phone's built-in filter and your carrier's basic spam service are free. Paid options from carriers add extra features, but most people do not need them. Start with the free tools first.

Can I block text messages from spam numbers?

Yes, but separately from calls. On iPhone, open Messages, find the conversation, swipe left, and tap "Block." On Android, open Messages, press and hold the conversation, and tap "Block." You can also block a number in your Contacts app on either phone.