How to Block a Number on a Landline Phone

Unwanted calls on a landline can range from mildly annoying to genuinely disruptive — telemarketers, robocalls, or persistent unknown numbers that seem to call at the worst times. The good news is that blocking numbers on a landline is absolutely possible. The methods available to you, however, depend on your phone service type, your equipment, and your carrier. Here's a clear breakdown of how it all works.

How Landline Call Blocking Actually Works

Unlike smartphones, which have built-in software tools for blocking calls, landlines operate through the public switched telephone network (PSTN) or, increasingly, Voice over Internet Protocol (VoIP). This distinction matters because it shapes which blocking options are available to you.

On a traditional landline, your phone itself has no operating system capable of filtering calls independently — it simply rings when the network tells it to. That means blocking must happen at the network level (your carrier), at an intermediary device (like a call-blocking unit), or through a service layer sitting between the caller and your phone.

Method 1: Use Your Carrier's Built-In Call Blocking

Most major phone carriers — whether traditional PSTN providers or VoIP-based home phone services — offer some form of selective call rejection or call blocking.

How to set it up:

• Log into your carrier's online account portal
• Look for call management, privacy, or security settings
• Add specific numbers to a blocked list

Some carriers also let you activate blocking by dialing a feature code directly from your handset. A common example is *60, which enables selective call rejection on many North American landline services. After activating it, you can add the last incoming number automatically or enter numbers manually.

What to know: Carrier-based blocking typically allows a limited number of entries (often between 25 and 100 numbers). This works well for blocking specific known numbers but won't stop spoofed numbers or robocalls that rotate through different caller IDs.

Method 2: Dedicated Call-Blocking Devices 📵

A call-blocking device plugs into your existing landline setup — usually between the phone jack and your handset — and filters calls before they reach your phone.

These devices work by:

• Matching incoming caller IDs against a blacklist (numbers you've manually blocked)
• Cross-referencing against a community-sourced database of known spam or robocall numbers
• Requiring unknown callers to announce themselves or press a key before the call connects

Some devices combine all three approaches. The key variable is whether the device updates its spam database automatically (requiring an internet connection or subscription) or relies solely on a static local list you maintain yourself.

Best suited for: Households that receive frequent robocalls and want a hardware solution that doesn't require monthly service changes or ongoing carrier involvement.

Method 3: Register With the Do Not Call Registry

In the United States, registering your landline number with the National Do Not Call Registry (donotcall.gov) is a baseline step worth taking. Legitimate telemarketers are legally required to honor it.

Important caveat: This does not block calls. It reduces them from compliant businesses. Political organizations, charities, survey companies, and scammers are not bound by it — and scammers, by definition, ignore it entirely. Think of registry registration as one layer in a broader strategy, not a complete solution.

Method 4: VoIP Landline Services — More Flexibility 🔧

If your home phone runs through a VoIP provider (such as a cable company's digital phone service or a standalone VoIP service), you often have significantly more blocking power available.

VoIP systems process calls digitally, which means the provider can apply more sophisticated filtering rules:

• Block entire area codes or number prefixes
• Enable anonymous call rejection (blocking calls with no caller ID)
• Apply time-of-day restrictions
• Use AI-based spam detection that updates in real time

These features vary widely between providers. Some include them in the base plan; others charge extra for advanced call management packages.

Method 5: Anonymous Call Rejection

If you're being bothered specifically by callers who block their caller ID, many carriers support anonymous call rejection via the feature code *77. When enabled, callers who have suppressed their number hear a message saying you don't accept anonymous calls. They must unblock their number to get through.

To turn it off, you typically dial *87.

This is a simple, no-cost option on most traditional landline plans and requires no device or service upgrade.

Comparing Your Options

The Variables That Change Everything

What works well for one household may be completely ineffective for another. The factors that matter most:

• Service type: Traditional copper-line PSTN, fiber-based landline, or VoIP — each has different capabilities
• Carrier: Feature availability and included services vary significantly between providers
• Call volume and type: A few recurring numbers vs. a flood of rotating robocalls require different approaches
• Technical comfort level: Feature codes and online portals are straightforward; some call-blocking hardware has more setup complexity
• Budget: Carrier add-ons and hardware devices come at different price points

Someone on a legacy copper landline with a basic carrier plan has a different toolkit than someone using a VoIP home phone through a major cable provider. The right combination of methods — and how much blocking power you actually need — depends entirely on what kind of service you're running and what you're trying to stop.