Blocking a number on a landline depends on what your phone company offers

Most landline providers offer call blocking as a feature you can turn on through your phone settings, your account online, or by calling customer service. The exact method varies by provider — Verizon, AT&T, Comcast, and smaller regional carriers each have different systems. Some let you block numbers directly from your phone's handset; others require you to manage blocks through a website or app; still others require a phone call to customer service to add a number to your block list.

The good news is that call blocking on a landline is usually free or costs a few dollars per month, and it works at the network level — meaning the call is blocked before it reaches your phone, not after. This is different from a cell phone, where some blocking happens on your device itself.

Before you start, check what your provider offers. Call your landline company's customer service number (usually on your bill) and ask whether they offer call blocking, what it costs, and whether you can manage it yourself or need their help to add numbers.

Key Takeaways

  • Most landline providers offer call blocking for free or a small monthly fee, and you can usually manage it online, through your phone, or by calling customer service.
  • Network-level blocking stops calls before they reach your phone, which is more effective than device-level blocking because it prevents the call from ringing at all.
  • Some providers let you block numbers from your handset's menu; others require you to log into your account online or call customer service to add numbers to a block list.
  • If your provider does not offer call blocking, third-party devices like call-blocking boxes can sit between your phone line and your handset to filter incoming calls.

How to block a number through your landline provider's system

Start by finding out which method your provider uses. Verizon customers can usually manage blocks through the My Verizon app or website, or by dialing *60 from their landline phone and following the voice prompts. AT&T offers a similar feature called Call Protect, which you can manage online or through their app. Comcast (Xfinity Voice) lets you block numbers through your online account dashboard.

If your provider offers online management, log into your account, look for a section called "Call Blocking," "Call Management," or "Preferences," and add the number you want to block. Most systems let you enter the full phone number and will confirm the block is active. If you prefer to do it by phone, call your provider's customer service line and ask them to add the number to your block list — they will need the phone number you want blocked and may ask why you want it blocked, though they usually do not require a reason.

Once a number is blocked, calls from that number will not ring through to your phone. Some providers send you a notification that a blocked call came in; others do not. If the caller uses a different number, that new number will ring through unless you block it separately.

Blocking numbers directly from your phone handset

Some landline phones, especially newer models or those with digital displays, let you block a number right from the handset without logging into an account. If you have a call from a number you want to block, look for a "Block" or "Reject" button on your phone's keypad or menu screen. Press it while the call is coming in or immediately after it ends, and the phone will add that number to a local block list.

This method works best if your phone has a display screen that shows the incoming number. Older rotary or basic push-button phones usually do not have this feature. Check your phone's manual or call your provider to ask whether your specific handset supports call blocking from the device itself.

Be aware that handset-level blocking only works on that particular phone — if you have multiple phones on the same landline, you will need to block the number on each one separately. Network-level blocking through your provider works across all phones on your line, which is why it is usually the better option if your provider offers it.

Using third-party call-blocking devices if your provider does not offer blocking

If your landline provider does not offer call blocking, or if you want an additional layer of protection, you can buy a standalone call-blocking device. These sit between your phone line (where it enters your home) and your phone handset, and they filter incoming calls based on rules you set.

Common options include the CPF32 Call Blocker (a small box that plugs into your phone line and lets you block up to 1,500 numbers), the Nomorobo device (which connects to your phone line and uses a database of known spam numbers), or the ClearCall device (which blocks calls based on patterns and caller ID information). Prices range from around $30 to $150 depending on the model and features.

These devices work by intercepting calls before they reach your phone. You usually program blocked numbers into the device using its keypad or a companion app, and the device will not let those calls through. The downside is that you have to buy and install the hardware, and you are responsible for maintaining the block list — your provider is not managing it for you.

What happens when a blocked call tries to reach you

When a call from a blocked number reaches your line, the call is typically disconnected at the network level. The caller usually hears a message saying the number is not in service, or the call simply drops. You will not hear your phone ring, and in most cases you will not be notified that a blocked call came in — though some providers do send a notification or log the attempt.

This is different from a cell phone, where a blocked call might go to voicemail or the caller might hear a message saying the call could not be completed. Landline blocking is more complete because it stops the call before it even reaches your home.

If you block a number by mistake, you can unblock it through the same method you used to block it — either through your provider's website, by calling customer service, or through your phone's menu if you blocked it at the handset level.

Dealing with spoofed or unknown numbers

Spam callers often use spoofed numbers — fake caller IDs that look like they are coming from a local number, a government agency, or a business you recognize. Blocking the number they show does not help, because the next call will come from a different spoofed number.

For this reason, call blocking works best against repeat callers from the same number. If you are getting spam from constantly changing numbers, blocking individual numbers is not an effective solution. Instead, ask your provider whether they offer spam filtering or robocall detection as part of their service. Many providers now include this at no extra cost — Verizon's Call Filter, AT&T's Call Protect, and Comcast's Xfinity Voice all have spam detection built in.

You can also register your landline number on the National Do Not Call Registry at donotcall.gov. This does not stop all spam calls, but it is a legal requirement that telemarketers honor it, and it can reduce the volume of unwanted calls over time.

Frequently Asked Questions

Can I block a number if I do not know who it is?

Yes. You do not need to know who is calling to block a number — you only need the phone number itself. If you see a number on your caller ID that you do not recognize and do not want to hear from, you can block it immediately. Your provider will not ask you to justify the block.

If I block a number, can the caller leave a voicemail?

No. When a number is blocked at the network level, the call does not reach your phone at all, so the caller cannot leave a voicemail. If you are using a third-party device, the behavior depends on how the device is configured — some let blocked calls go to voicemail, others do not.

What if the same person calls from different numbers?

You will need to block each number separately. If someone is harassing you from multiple numbers, contact your local police or your provider's abuse team — they may be able to help beyond simple call blocking. Repeated harassment from changing numbers can sometimes be addressed through legal channels.

Does call blocking work on international numbers?

Yes, you can block international numbers the same way you block domestic ones. Enter the full number including the country code (for example, +44 for the United Kingdom) into your provider's block list or your phone's menu, and it will be blocked like any other number.

Will blocking a number stop text messages from that number?

Landline call blocking only stops phone calls, not text messages, because landlines do not receive text messages. If you are receiving unwanted texts on a cell phone, you will need to use your phone's built-in text-blocking feature or contact your cell provider for SMS filtering options.