How to Block No Caller ID Phone Calls on Any Device

Calls from hidden or blocked numbers are one of the more frustrating parts of modern phone ownership. Whether it's telemarketers, robocalls, or genuinely unknown parties, No Caller ID calls show up without any identifying information — and blocking them isn't always straightforward. The good news: there are several real, working methods. Which one fits depends on your device, carrier, and how aggressive you want the block to be.

What "No Caller ID" Actually Means

When a call shows No Caller ID on your screen, the caller has deliberately suppressed their number using a feature called Caller ID blocking. This is different from an "Unknown" call, which typically means the number couldn't be identified by your carrier's database.

Callers suppress their number by:

• Dialing *67 before the number (in the US and Canada)
• Enabling permanent Caller ID blocking through their carrier account
• Using certain VoIP apps or services that allow number masking by default

Because no number is transmitted, standard spam-blocking apps that work by recognizing known bad numbers can't flag these calls — there's simply nothing to match against.

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

Most major carriers offer tools specifically designed to block anonymous calls:

Many of these services include an option to send anonymous calls directly to voicemail or block them outright. This is often the cleanest solution because it works at the network level — before the call ever reaches your phone.

The limitation: some carrier tools sit behind a paid tier. The free version may only filter known spam numbers, leaving No Caller ID calls to pass through unless you upgrade.

Method 2: iPhone Settings — Silence Unknown Callers

Apple introduced a native feature called Silence Unknown Callers, available in iOS 13 and later.

To enable it: Settings → Phone → Silence Unknown Callers → Toggle on

When active, any call not in your contacts, recent calls, or Siri Suggestions is automatically silenced and sent to voicemail. This does catch No Caller ID calls, since a suppressed number has no identifying match.

The trade-off is significant: it's a broad filter. If you're expecting calls from numbers not in your contacts — doctors' offices, delivery services, clients — those will be silenced too. It's a blunt instrument, not a surgical one.

Method 3: Android Settings and Google Phone App

Android doesn't have a single universal setting because the experience varies across manufacturers. However, if you're using the Google Phone app (standard on Pixel devices and available on many Android phones):

To filter unknown calls: Phone app → Three-dot menu → Settings → Spam and Call Screen → Filter spam calls

Google's call screening feature can also be set to automatically screen calls from unknown numbers, reading a transcript of what the caller says before you decide to answer.

On Samsung devices, Smart Call settings include options to block unidentified private numbers specifically. The path varies by One UI version.

🔍 Key distinction: Android filtering options often separate "unknown numbers" from "private/hidden numbers." Look specifically for language like private, anonymous, or hidden number in your settings to make sure you're targeting No Caller ID calls specifically.

Method 4: Third-Party Call Blocking Apps

Apps like Hiya, Nomorobo, and Robokiller (among others) offer No Caller ID blocking as part of their feature sets. These typically work by:

• Integrating with your phone's call screening API
• Automatically rejecting calls with no transmitted number
• Sending silent calls to voicemail with optional transcription

Performance and feature availability vary based on your OS version, phone model, and whether the app has the necessary permissions. Some require a subscription for the anonymous call blocking feature specifically.

Method 5: Ask Your Carrier to Enable Anonymous Call Rejection (ACR)

Many carriers support a network-side feature called Anonymous Call Rejection. In the US, you can often activate this by dialing *77 from your phone. To deactivate, dial *87.

This is one of the most underused methods. It works at the carrier level, costs nothing on most plans, and specifically targets calls where Caller ID has been suppressed. The rejected caller hears a message telling them their call cannot be completed until they unblock their number.

The Variables That Shape Your Results

No single method works the same way for everyone. What matters:

• Your carrier — network-level tools vary significantly in scope and cost
• Your device OS and version — Silence Unknown Callers requires iOS 13+; Google's call screen features aren't available on all Android builds
• Your phone app — stock dialer vs. Google Phone vs. manufacturer dialer each have different settings
• How broadly you want to block — some methods block all unknown calls, others only No Caller ID specifically
• Whether you receive legitimate calls from unknown numbers — a broad block solves one problem while creating another

Someone who only uses their phone for personal contacts and wants zero anonymous calls has very different needs than someone running a small business who regularly gets first-contact calls from unknown numbers. The same setting that works perfectly for one situation creates real problems for the other.