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

Most landline providers offer call blocking as part of their service, but the method varies by company. Some let you block numbers directly through your phone's built-in features, others through a phone company app or website, and some require you to call customer service. The fastest way to find out what you have is to check your phone's menu or log into your phone company's account online — you may already have blocking tools available that you have not used yet.

The blocking tools that work best are the ones your phone company controls, because they stop the call before it reaches your phone. This is different from a device-level block, which silences the call but still rings through. If you are getting many unwanted calls, a phone company block is worth setting up first.

Key Takeaways

  • Most landline companies offer call blocking through their website, app, or by phone — check your bill or log into your account to see what is available to you.
  • Phone company blocks stop calls before they ring, while device-level blocks only silence them after they arrive.
  • If your landline phone has a menu button, you can often block numbers directly from the call history without contacting your provider.
  • Robocalls and spam often use fake numbers that change each time, so blocking individual numbers works best for calls from real people or businesses that call repeatedly.
  • If blocking through your phone company does not work, ask them about call filtering services, which catch more spam than manual blocking alone.

Blocking a number through your phone company's website or app

Log into your phone company's online account or open their mobile app. Look for a section labeled "Call Blocking," "Manage Calls," "Call Settings," or "Phone Features." Most major providers — AT&T, Verizon, CenturyLink, Frontier, and others — have this section visible from the main account menu.

Once you find it, you will usually see an option to add a number to a blocked list. Enter the phone number you want to block and confirm. The block typically takes effect within a few minutes. Some phone companies let you block up to 30 numbers for free; others charge a small monthly fee (usually $3 to $5) for unlimited blocking. Check what your plan includes before you add numbers.

If you cannot find the blocking feature online, call your phone company's customer service number — it is on your bill. Tell them you want to block a specific number, and they can set it up for you over the phone in about five minutes. Write down the number you want blocked before you call so you do not have to search for it during the conversation.

Blocking a number directly from your landline phone

Many modern landline phones have a built-in block feature. After you receive a call you want to block, look for a Menu or Settings button on the phone itself. Press it and navigate to "Call History," "Recent Calls," or "Block List" — the exact wording depends on your phone model.

Find the number you want to block in the call history, select it, and look for an option that says "Block," "Block Number," or "Add to Block List." Confirm the selection. The phone will now reject calls from that number. This method works on most cordless and digital landline phones made in the last ten years, but not on older rotary or basic push-button phones.

If your phone does not have a menu, or if you cannot find the blocking option, your phone model does not support device-level blocking. In that case, use your phone company's website or call them directly — that is your only option.

Why blocking individual numbers often does not solve spam

Robocalls and spam calls usually come from numbers that change every time. Blocking one number stops that one call, but the same caller will reach you from a different number the next day. If you are blocking more than a few numbers a week, individual number blocking will not solve your problem.

For persistent spam, ask your phone company whether they offer a call filtering service. Services like AT&T Call Protect, Verizon Call Filter, or similar tools from other providers use algorithms to identify spam patterns and block calls before they reach you. These services catch far more spam than manual blocking, though they are not perfect. Some are free, others cost $3 to $5 per month. Ask your provider what they offer and whether it is included in your plan.

What to do if blocking does not work

If you blocked a number through your phone company but the calls keep coming, the caller may be spoofing their number — using technology to make their call appear to come from a different number each time. Spoofed calls cannot be blocked by number because the number is fake. In this case, call your phone company and ask whether they can identify the actual source of the calls. Some providers have tools that can trace spoofed calls and block them at the network level.

If the calls are from a business or debt collector, you may have legal options beyond blocking. You can send a written request to stop calling, and some types of calls are illegal to make to landlines. Your phone company's customer service can tell you whether the calls violate regulations in your area.

If blocking through your phone company does not work and you have tried their call filtering service, consider a third-party device like a call blocker box. These devices sit between your phone line and your phone and filter calls before they reach the handset. They cost $30 to $100 and work independently of your phone company, so they can block calls that slip through your provider's system.

Setting up a do-not-call list entry

If you are getting unwanted sales calls, register your landline with the National Do Not Call Registry. Telemarketers are required by law to stop calling numbers on this list, though the rule does not apply to charities, political organizations, surveys, or debt collectors. You can register at donotcall.gov or by calling 1-888-382-1222 from the phone you want to register.

Registration is permanent and free. You will not see results immediately — it can take up to 31 days for telemarketers to update their lists. If you keep getting sales calls after that period, you can file a complaint on the same website, and the Federal Trade Commission will investigate.

Frequently Asked Questions

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

Yes. If you see a number in your call history that you do not recognize, you can block it through your phone company or your phone's menu without knowing who it is. If the calls continue from different numbers, the caller is likely spoofing, and blocking individual numbers will not help — ask your phone company about network-level blocking instead.

Will the blocked caller know they are blocked?

No. When you block a number through your phone company, the call is rejected at the network level before it reaches your phone. The caller hears a message saying the call cannot go through, but they will not know it was blocked by you specifically. They may think the number is disconnected or invalid.

How many numbers can I block?

Most phone companies allow you to block 30 numbers for free. If you need to block more, they usually offer an unlimited blocking service for a monthly fee of $3 to $5. Check your phone company's website or call them to see what your plan includes.

What is the difference between blocking and call filtering?

Blocking stops calls from specific numbers you add to a list. Call filtering uses algorithms to identify spam patterns and blocks calls automatically without you having to add each number. Filtering catches more spam but is not perfect and may occasionally block legitimate calls.

Do I need to pay to block a number?

Most phone companies let you block up to 30 numbers for free. Unlimited blocking and call filtering services usually cost $3 to $5 per month. Check your phone company's website to see what is included in your current plan before you pay for an upgrade.