How to Block a Phone Number on a Landline

Can you block a number on a landline at all?

Yes, but a landline works differently from a mobile. The phone on your table usually has no blocking list of its own, so the block has to live either in the handset base unit, in a small device plugged in front of the phone, or with the telephone company that provides the line. A landline is a phone line delivered to a fixed address, whether over copper wire, cable or your internet connection.

Which of the three you use depends on your equipment. Work through them in order of effort: the handset first, then the carrier service, then extra hardware only if neither is enough.

How do you block a number using the carrier's call block code?

Most home phone providers support a per-line block service that you switch on from the handset by dialling a short code that starts with a star. The service is usually called call block, call screening or selective call rejection, and it holds a limited list of numbers, often a couple of dozen.

1. Pick up the handset and listen for a dial tone. If there is no dial tone, nothing else in this list will work.
2. Dial the call block code for your provider. If you do not know it, look it up under your provider's name and the words "selective call rejection" rather than guessing, since codes differ between providers.
3. Listen to the recorded menu. It will tell you how many numbers are already on the list and which key adds a new one.
4. Add the number. To add the caller who just rang, there is usually a single key that blocks the last incoming call without you typing anything.
5. Type the full number with the area code when you enter one manually, then wait for the confirmation message before hanging up.

Two conditions matter here. The service has to be active on your line, and on some plans it is switched on by request rather than by default. And the list has a fixed size, so once it is full you must remove an old entry before adding a new one.

How do you block a number on a cordless phone or answering machine base?

Many cordless handsets sold in the last few years have their own block list built into the base unit, which works even if your provider offers nothing.

1. Open the menu on the handset and look for call block, blocked calls or call guard.
2. Choose the option to add a number, then either type it or pick it from the recent calls list.
3. Save, then check the entry appears in the stored list. Some handsets need you to confirm twice.
4. Note the list size shown in the manual. These lists are usually small, and a full list silently refuses new entries on some models.

If your handset offers a setting to block all calls with no caller ID, or to block a whole prefix, that is often more useful than blocking one number at a time.

What if your landline runs through the internet or a cable box?

If your home phone came bundled with internet or television, the blocking controls are usually in your online account rather than on the phone. Sign in to the account at the company’s official website, find the section for your home phone service, and look for call blocking or call controls there. Changes made in the account apply to the line itself, so they work whichever handset is plugged in.

This route often gives you more than the star codes do: a longer list, a setting for anonymous callers, and sometimes a screening service that asks unknown callers to identify themselves before the phone rings.

Why do blocked callers still get through?

Blocking one number stops one number, and that is the root of most disappointment.

• Spoofing. The caller forges the number shown on your display, so every call arrives from a different one. Blocking the last one has no effect on the next.
• Withheld numbers. If no number is delivered, there is nothing to add to a list. You need the setting that rejects anonymous calls instead.
• Wrong format. The number was stored without the area code, or with a leading digit the network does not expect, so it never matches.
• A full list. The entry was never saved because the block list had already reached its limit.
• The wrong layer. You blocked the number on the handset, but the call reaches an answering machine or a second phone on the same line that does not share that list.

What stops repeated unwanted calls better than blocking?

When numbers keep changing, switch from blocking individual callers to filtering the whole line.

• Turn on the anonymous call rejection option if your provider has one. It refuses calls that hide their number.
• Ask your provider about a screening service, where unknown callers must announce themselves or press a key before your phone rings. Machines almost never get past it.
• Consider an in-line call blocker device that sits between the wall socket and the phone. These hold much larger lists and can block entire ranges.
• Register the line on the national do-not-call list. It does not stop scammers, but it removes lawful marketing calls over time.
• Do not press a key to be removed from a list during a recorded call. On an unsolicited call that confirms a real person answers.

How do you check what is currently blocked, or undo a block?

Dial the same call block code and listen to the menu: it reads back how many numbers are stored and offers options to hear the list, remove one entry, or clear everything. On a handset, the same menu that added the number will show the stored list. Removing a number takes effect immediately, which matters if you have blocked a clinic or a school by mistake.

When should you contact your phone company?

Contact them when the star code gives an error or a fast busy tone, when the block service is not on your plan, when the calls are threatening, or when the same caller reaches you despite a confirmed block. Before you call, write down the exact number as it appeared, the dates and times of several calls, what you already tried, and whether the calls come at a pattern. That record is what turns a complaint into a case they can act on, and it is also what a law enforcement report will ask for if the calls are threatening.