What call blocking does and where to find it

Call blocking stops incoming calls from reaching your phone — either by preventing them from ringing through at all, or by sending them to voicemail without alerting you. Most phones come with built-in blocking tools, and your phone service provider (the company you pay for your phone line) usually offers additional blocking at no extra cost.

The blocking happens at different points depending on which tool you use. Your phone's own settings block calls before they reach your device. Your provider's blocking service stops calls at their network level, which means the call never even tries to connect to your phone. Some people use both together for stronger protection.

You do not need special software or a paid subscription to block calls. The tools described here are included with your phone or your service plan.

Key Takeaways

  • Your phone has a built-in block list where you can add numbers manually, and most phones also let you block calls from unknown numbers entirely.
  • Your phone service provider offers network-level blocking that stops calls before they reach your device, and you can turn this on through your account or by calling customer service.
  • Spam calls often use fake numbers that change with each call, so blocking individual numbers is less effective than blocking by category (unknown callers, likely spam).
  • Do not return calls to numbers you do not recognize, because some scams charge you money just for calling back.
  • If you need to receive calls from unknown numbers for work or medical reasons, you can whitelist specific numbers instead of blocking all unknowns.

Blocking calls on your phone itself

Every smartphone has a built-in block list. On iPhone, open the Phone app, find the number you want to block in your recent calls or contacts, tap the information icon (the small circle with an "i"), scroll down, and tap "Block this Caller." On Android, open the Phone app, press and hold the number, and select "Block number" from the menu that appears.

Once a number is on your block list, calls from that number go straight to voicemail and you receive no notification. The caller will not know they were blocked — they will just hear a message that your voicemail is unavailable or that the call could not go through.

Blocking individual numbers works well if you are getting repeated calls from the same person or business. It does not work well against spam, because spam callers use different numbers for each call. If you are receiving many spam calls, blocking by category is more effective: on iPhone, go to Settings > Phone > Silence Unknown Callers to send all calls from numbers not in your contacts straight to voicemail. On Android, open the Phone app, tap the three-line menu, go to Settings > Spam and Call Screen, and turn on "Filter Unknown Calls."

Using your phone service provider's blocking tools

Your phone company (AT&T, Verizon, T-Mobile, or your regional provider) runs blocking services at the network level, meaning they stop calls before your phone even rings. These services are usually free or cost a few dollars per month, and you turn them on through your account online or by calling customer service.

AT&T offers Call Protect, which blocks known spam and scam numbers automatically. You can view blocked calls in the AT&T mobile app. Verizon offers Call Filter, which works the same way. T-Mobile includes Scam Shield at no cost, which blocks calls from numbers flagged as spam. If you use a smaller regional provider, call their customer service line and ask what spam blocking they offer — most have something.

These network-level services update their spam lists constantly, so they catch new spam numbers faster than you could block them manually. The downside is that they occasionally block legitimate calls by mistake. If you miss a call you needed, you can usually see it in a blocked calls log and add that number to a whitelist so future calls from it go through.

Handling calls from numbers you do not recognize

If you receive a call from a number you do not recognize, the safest approach is to let it go to voicemail. If it is important, the caller will leave a message. If it is spam, they usually will not.

Do not call back a number you do not recognize, especially if the caller claimed to be from your bank, the IRS, or a utility company. Some scams are designed so that calling back charges you money — either through premium phone numbers or through charges that appear on your bill later. If you think a call might be legitimate, hang up and call the organization directly using a number from their official website or your bill.

If you need to receive calls from unknown numbers because of work or medical reasons, you can whitelist specific numbers instead of blocking all unknowns. Ask the person or organization to give you the exact number they will call from, then add it to your contacts. Calls from numbers in your contacts will come through even if you have unknown caller blocking turned on.

What to do about robocalls and spoofed numbers

Robocalls are automated calls, usually recorded messages. Spoofing is when a caller makes their number appear to be something it is not — for example, a scammer might make their call look like it is coming from your bank. Both are common, and both are difficult to stop completely because the caller is using fake information.

Your phone company's spam blocking service catches many robocalls and spoofed numbers by comparing incoming calls against known spam patterns. If you are still receiving many robocalls after turning on your provider's blocking, you can register your number with the National Do Not Call Registry at donotcall.gov. This is free and takes two minutes. It does not stop all robocalls — scammers ignore the registry — but it does reduce calls from legitimate telemarketing companies.

If a robocall is particularly aggressive or threatening, you can report it to the Federal Trade Commission at reportfraud.ftc.gov. The FTC tracks patterns and sometimes takes action against the worst offenders, though individual reports rarely result in when ready action.

Managing voicemail when calls are blocked

When a blocked call goes to voicemail, it appears in your voicemail inbox like any other missed call. On iPhone, you can delete blocked voicemails without listening to them. On Android, blocked voicemails usually appear in a separate spam folder in your voicemail app, so they do not clutter your main inbox.

If you block a number and later realize you need to hear messages from it, you can unblock 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.

Some people keep their block list as a way to track which numbers have bothered them. Others clear it regularly. There is no right approach — use it however makes sense for your situation.

When blocking is not enough

If you are receiving dozens of calls per day despite blocking and your provider's spam filter, you may be dealing with a targeted scam or harassment campaign. In this case, contact your phone company's customer service and ask to speak with someone about the volume of calls. They can sometimes explore additional filtering or investigate whether your number has been compromised.

If the calls are threatening or harassing, you can report them to local police. Keep a record of the dates, times, and content of the calls if possible. If the calls are related to debt collection, you have additional legal protections — debt collectors are not allowed to call repeatedly or at unreasonable hours, and you can send them a written request to stop calling.

If you think your phone number has been sold to scammers or used fraudulently, consider changing your number. This is inconvenient, but it is sometimes the only way to stop a flood of unwanted calls. Your phone company can help you port your number to a new one.

Frequently Asked Questions

Will someone know if I blocked their number?

No. When you block a number, calls from that person go to voicemail without any notification to them. They will not receive a message saying they were blocked. They may eventually realize it if they never get a response, but the phone system itself does not tell them.

Can I block text messages from the same number as calls?

Yes. When you block a number on your phone, it blocks both calls and text messages from that number. On iPhone, you can also block a contact by opening a text message from them, tapping the contact name at the top, and selecting "Block this Caller." On Android, open the text message, tap the three-dot menu, and select "Block."

What is the difference between blocking and silencing a number?

Blocking sends calls straight to voicemail with no notification. Silencing (or muting) a contact lets the call ring through, but your phone does not alert you — the call goes to voicemail if you do not answer. Silencing is useful if you want to avoid a contact but do not want to completely block them.

Do I have to pay for my phone company's spam blocking service?

Most phone companies include basic spam blocking at no cost. Some offer premium versions with more features for a few dollars per month. Call your provider or check your account online to see what is included in your plan and what costs extra.

If I block unknown callers, will I miss important calls?

Possibly, if the caller does not have a contact saved in your phone. If you are expecting a call from a doctor's office, a delivery service, or another organization, ask them for the exact number they will call from and add it to your contacts before the call comes in. That way it will come through even if you have unknown caller blocking turned on.