The basic methods depend on your phone company and equipment
Most landline providers offer call blocking through their network, meaning the block happens before the call reaches your phone. You can also block calls at the phone itself using your handset's built-in features, though this only works if your phone has that capability. The network-level option is usually more reliable because it stops the call from coming through at all, while handset blocking just silences or rejects calls that still arrive.
Which method works for you depends on three things: whether your phone company offers the service, whether you have a modern phone with blocking features, and how much control you want over which calls get through. Most people use a combination of both.
Key Takeaways
- Call blocking through your phone company stops calls before they reach your phone and usually costs nothing or a few dollars per month.
- Your landline phone itself may have a block list if it is a newer model with a digital display and menu system.
- To block a number through your phone company, call their customer service line and give them the specific number you want blocked.
- Handset blocking works only for calls that come through; network blocking prevents the call from arriving at all.
- If your phone company does not offer blocking, a third-party device that sits between your phone and the wall jack can filter calls.
Blocking through your phone company's network
Call your landline provider's customer service number — it is on your bill or their website — and ask for call blocking or call screening. Most major providers offer this at no charge or for a small monthly fee, usually between $3 and $5. Tell the representative the phone number you want blocked, and they will add it to your account.
The block takes effect within a few hours to a day. When someone calls from that number, they will either hear a message saying the call cannot be completed, or the call will not ring through at all. Some providers let you block up to 30 numbers; others have higher limits. Ask how many numbers your plan allows before you hang up.
If the same person calls from different numbers, you will need to block each one separately. This is why network blocking works best for one or two persistent callers rather than for spam calls that rotate through hundreds of numbers.
Blocking calls on the phone itself
If your landline phone has a digital display and a menu button, it likely has a built-in block list. Look for a button labeled Menu, Settings, or Options. Navigate to Call Blocking, Blocked Calls, or a similar option. The exact path varies by phone model, so check the manual or the manufacturer's website if you are unsure.
Once you find the block list, you can usually add a number by pressing a button during or right after a call from that number, or by manually entering the number through the menu. The phone will then reject or silence calls from that number. Some phones let you block up to 50 numbers; others hold fewer.
Handset blocking has a limitation: the call still comes through to your phone's system, so your phone will still ring or show a missed call. It just will not alert you in the normal way. This is less effective than network blocking if you want to avoid being disturbed at all.
What to do if your phone does not have built-in blocking
Older landline phones without a digital display do not have blocking features. If your phone company does not offer network blocking either, you have two options: replace the phone with a newer model that has blocking, or use a third-party device.
A call-blocking device sits between your phone jack and your phone. It monitors incoming calls and blocks numbers on its internal list. Models like the CPF32 or similar devices cost $30 to $60 and do not require installation by a technician — you just plug them in. These devices work with any phone and any phone company.
The trade-off is that you have to manage the block list on the device itself rather than through your phone company's system. Some devices let you add numbers through a small keypad; others require you to use a computer or app. Check the product description before buying to make sure the interface works for you.
Handling spam and robocalls on a landline
Network blocking and handset blocking both work for individual numbers, but spam calls often come from rotating numbers, so blocking one number does not stop the next call from the same scammer. For spam, your phone company may offer a separate service called spam filtering or robocall blocking.
Ask your provider whether they offer spam filtering — some include it free, others charge $2 to $4 per month. This service uses algorithms to identify likely spam calls and either blocks them or marks them as spam so you know not to answer. It is not perfect, but it catches most automated calls.
If your provider does not offer spam filtering, the third-party devices mentioned above sometimes include spam detection as well. Check the product details to see whether it blocks only numbers you add manually or whether it also filters known spam patterns.
Blocking calls from unknown or private numbers
Some callers hide their number and show up as "Unknown," "Private," or "Blocked" on your caller ID. You can block all calls from hidden numbers through your phone company — ask them about blocking anonymous calls or calls with no caller ID. This is a single setting rather than adding individual numbers.
The downside is that some legitimate callers, including hospitals and government offices, sometimes use hidden numbers. If you block all anonymous calls, you might miss important calls. A middle ground is to let them ring but not answer, so you can listen to a voicemail and call back if it is important.
If your phone has a built-in block list, check whether it has an option to block private numbers as a category rather than requiring you to block each number individually. Most modern phones do offer this.
What happens after you block a number
The caller will not hear a message saying they are blocked. Instead, they will hear a standard message like "the call cannot be completed as dialed" or the call will straightforward not go through. They may not realize they are blocked; they might assume your line is busy or out of service.
If you block a number and then change your mind, you can unblock it by calling your phone company or accessing your phone's menu. Most systems let you remove a blocked number in seconds. Keep in mind that blocking is not the same as reporting a number — if you want to report spam or harassment to authorities, that is a separate step.
Frequently Asked Questions
Can I block a number that shows up as unknown or private?
Yes, but you will be blocking all calls from hidden numbers, not just one caller. Ask your phone company about blocking anonymous calls, or check your phone's menu for an option to block private numbers. This means you will miss calls from any source that hides their number, including some hospitals and government offices.
What if the same person keeps calling from different numbers?
Network blocking requires you to block each number separately, which becomes impractical if someone is cycling through many numbers. In that case, consider spam filtering through your phone company, or contact local police if the calls are harassing or threatening. Some phone companies will also note a pattern and block all numbers from a range if you report repeated harassment.
Does blocking a number cost money?
Network blocking through your phone company is free with most providers, though some charge $3 to $5 per month for the service. Handset blocking built into your phone costs nothing. Third-party blocking devices cost $30 to $60 upfront. Check your phone bill or call your provider to see what they offer at no charge.
Can I block calls from my phone company itself?
Yes, you can block any number, including your phone company's. However, if you block their customer service line, you will not be able to reach them if you need help with your account. Consider whether you might need to contact them before blocking their number.
Will the person I block know they are blocked?
No. They will hear a standard message saying the call cannot be completed, or the call will not go through. They will not receive a notification that you blocked them. If they call from a different number, that call will come through unless you block that number too.