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How to block a number on a landline

Setting up spam protection on a landline might seem tricky, but it’s definitely possible.

There are many options to choose from: apps, devices, and registries—all depending on your phone or handset, service provider, and the type of landline you have.

It’s easy to get confused by all the choices—even if you’re quite familiar with modern tech.

For seniors, it can be a lot.

We’ve made this guide to make blocking unwanted calls on a landline achievable for everyone.

Let’s go through it step by step.

Updated: September 29, 2026

If you’re looking for a free solution, focus on the star-code and settings options below rather than paid devices or services.

While these solutions will help reduce spam calls, they probably won’t eliminate them entirely. Plus, blocking numbers and opting out of data brokers will take some time and effort.

If you’d like to learn how to carry out each of these steps—and see some additional options—check out our step-by-step guide below.

Stop unwanted calls at the source 

It’s better to fix the root cause of a problem, not just cover up the symptoms. 

If you want to stop spam and scam calls for good, you need to find out where they’re coming from. 

The main sources are:

• marketers 
• data brokers.

Stop spam calls by signing up to the Do Not Call Registry

Start by adding your phone number to the National Do Not Call Registry. 

This is a service from the Federal Trade Commission (FTC) that helps reduce spam calls from marketers.

Once your number is on the list, it tells these companies not to call you.

Here’s how to sign up:

1. Go to the Do Not Call Registry website.
2. Click on “register your phone” and follow the steps.

It’s free to sign up.

If you prefer, you can call the FTC to register your number instead.

Dial 1-888-382-1222 (for voice calls) or 1-866-290-4236 (for TTY) from the phone number you want to add.

However, keep in mind that this service isn’t perfect. 

Some companies don’t follow the rules, and scammers aren’t stopped by it. That’s why it’s a good idea to remove your information from data brokers as well.

Stop spam calls by removing your data from brokers

Data brokers specialize in collecting your data and selling it for profit.

This can result in your home phone number being shared with bad actors.

Landline numbers are an easy target for these lists. 

They’re tied to public records like real estate and leases, and they often skew toward older callers—exactly who scammers go looking for. 

Call-blocking hardware only catches what reaches your phone. 

But removing your family’s number from the data brokers behind these lists cuts off the supply before it gets that far.

You can prevent scammers, fraudsters, and untrustworthy marketers from calling you by getting your number removed from data brokers’ lists.

Here’s how to do it:

• Use an automated service like Incogni 

Sign up, and Incogni will send removal requests to hundreds of data brokers right away.

It’s easy to set up and you’ll be taken care of by a team of professionals.

You can add multiple data points (like your landline and mobile phone number), sign up your family members, and keep track of the progress.

Alternatively—

Opt out manually

Many data brokers let you request the removal of your information for free, but you’ll need to opt out from many of them to make a real difference.

Unfortunately, they often make the process tricky, which can lead to a frustrating back-and-forth over email.

Click here to see a list of popular data brokers together with detailed opt-out guides.

Use call-blocking services for landline phones

Even if you’ve removed your information, there may still be people, including potential scammers, who have your number. 

It’s a good idea to block these calls from getting through to your phone. 

To do that, it’s important to know what kind of phone line you have. 

First, figure out what kind of landline you have

Before picking a blocking method, figure out whether you’re on a digital VoIP setup or a traditional analog copper line—some tools only work with one or the other.

Here’s the fastest way to check:

• VoIP (ISDN): Your home phone connects to an internet modem or router rather than directly to a wall jack. If you have internet-based phone service bundled with your broadband, you’re on VoIP.
• Copper (PTSN): The phone wire runs straight from the handset to the wall jack, with no modem or router in between. This is the traditional analog setup used by older landline installations.

This distinction matters because software solutions like Nomorobo only work over VoIP, while star codes and physical call-blocking hardware work on both line types.

Check if your provider already blocks spam calls

Before signing up for a separate tool, check what your own provider already offers. Landline and VoIP providers increasingly build call-blocking into their basic service:

• Xfinity Voice customers get the Xfinity Voice Spam Blocker, which labels risky calls automatically.
• Spectrum Voice includes Call Guard, which blocks and flags suspected robocalls by default for new customers.
• CenturyLink offers its own call-blocking tools through its customer portal.

Not all of these are free, and coverage varies by provider, so it’s worth checking your account settings or calling before assuming you need something else. The FCC keeps an updated list of what each major carrier offers.

Use spam-blocking software for landlines

If your phone is connected to VoIP, you can reduce spam calls by signing up for Nomorobo.par

Nomorobo is a free service that monitors incoming calls in real time and identifies any unusual patterns, like robocalls or spoofed numbers, that might be related to people trying to scam you.

Here’s how to use it:

• Go to nomorobo.com/signup/carrier.
• Choose your landline network provider.
• Enter your email address.
• Check your email for a message titled “Welcome to Nomorobo!” and click the link inside.
• Follow the steps to set up your Nomorobo account.
• Add your phone details.
• Set up your carrier (you might need to adjust some additional settings with your carrier).
• Confirm the service.

Nomorobo works through a feature called simultaneous ring: when someone calls, your phone and Nomorobo’s servers ring at the same time. 

If it’s a known robocaller, Nomorobo answers and hangs up before your phone gets past the first ring. No separate hardware required.

If you don’t have a VoIP connection or your carrier is not supported, consider installing a physical call-blocking device.

Read on to learn more.

Buy a physical call-blocking device to connect to your line

An alternative to Nomorobo is a physical device that screens incoming calls and blocks unwanted ones when necessary—some of them have a database of 100K reported numbers.

Additionally, you can add new numbers to the blocklist with just one click on the device, updating the list on the go. 

While setting up these devices is a bit more of a hassle than simply registering online, they can be very effective and worth the extra effort. 

There are many devices available on the market, here are some popular choices:

• CPR V5000 (~$90)
• CPR V100K (~$90)
• CPR V10000 (~$45)
• CPR Shield (~$35)
• Panasonic KX-TGA710B (~$100)
• Digitone ProSeries 3 (~$80).

Devices like the CPR Call Blocker series and Digitone boxes plug in inline between the wall jack and the telephone set, screening every call before it reaches the handset itself—no rewiring or professional installation needed.

Most of these devices are extremely easy to set up and don’t require any technical knowledge—just connect them with your phone and that’s it. Even elderly people should be easily able to set them up without too much trouble.

However, there’s a downside.

Call-blocking devices typically come with a predefined list of known scam numbers that cannot be updated by the manufacturer.

Since robocallers and scammers often change their numbers, these devices may become ineffective after some time.Get a handset with a call-blocking feature built into it

Get a handset with a call-blocking feature built into it

You might also think about getting a new phone that has call-blocking features built right in.

This works a lot like physical call-blocking devices, but it’s all integrated into the phone itself. Just keep in mind that it comes with the same limitations, meaning you’ll still have a predefined list of blocked numbers.

Here are some of the more popular handsets:

• Panasonic KX-TGD832M (~$40)
• AT&T GL2101-2 (~$35)
• Panasonic KX-TGF973B (~$150)

You don’t have to limit yourself to these options.

You can also browse Amazon for a phone that suits your needs—just make sure it includes a call-blocking feature.

Set up your devices to block spam

Consider this section your last line of defense.

If you’ve already removed your number from data brokers and set up a call-blocking device, most spam and unwanted calls should be blocked.

But if some still sneak through, here are a few extra tips to stop them.

Use star codes to block calls on landline phones

Most providers in the US let you turn on some handy features by dialing simple star codes to reduce unwanted calls.

Here’s a quick overview.

Dial *60 to block individual numbers

The catch is that you need to know the spammer’s number, meaning you’ll need to first receive a call before you can block the number.

Typically, you can block between 10 and 30 numbers.

Dial *77 to reject all anonymous callers

Once activated, calls that come through as “private,” “blocked,” or “anonymous” will not be allowed to reach your phone.

*AT&T notes that anonymous call rejection is not available in Illinois, Indiana, Michigan, Ohio, or Wisconsin.

Activate unknown caller authentication

The authentication feature isn’t available on every device (and might go by a different name).

Wondering how to check if you have it?

A good rule of thumb: if your phone has call blocking, it probably has call authentication too.

How does it work?

Call authentication is simple but really effective. It makes callers either press a button or announce who they are before the call goes through. If they don’t, your phone won’t even ring.

The idea is that real callers can easily press “1,” while robocallers and scammers using automated systems can’t.

This can seriously cut down on unwanted calls.

Setup depends on your device, so check your manual or look through the settings.

If it’s not an option, check out the next section for an alternative solution.

Create allowlists of good contacts and block other calls

This is another device-specific solution, but most modern phones should have some kind of allowlisting feature.

Here’s how you can use it to cut down on spam:

• Mute all callers except the ones on your allowlist
• Have unknown callers go through an authentication step if they’re not on the list.

Just take a look through your phone’s settings to find this feature. If it’s not there, you might need to buy a separate call-blocking device.

Setting up an allowlist can take a bit of time, especially if you have a lot of contacts, but it’s totally worth it in the long run.

If you’re also dealing with spam on a mobile line, our universal call guide covers the equivalent mobile settings, including iPhone and Android spam filtering.

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