Comparisons6 min read

What’s the Difference Between Unknown Caller and No Caller ID?

girl having call with an anonymous caller

Table of contents

Today, calling is one of the most preferred communication channels. And the call you are receiving does not have to be familiar to you. You may have got calls from an “Unknown Caller ID” or “No Caller ID.” Many think that both are the same, but they are not.


An “Unknown Caller” usually indicates that the network or device could not identify the caller’s information, while “No Caller ID” appears when the caller deliberately blocks their number to hide their identity.

What Does “Unknown Caller” Mean?

When a recipient gets a call flashing “Unknown” on the phone screen, you are getting a call from an Unknown Caller ID.


The “Unknown Caller” label indicates that your phone service provider does not recognize who is trying to contact you.


Receiving unknown calls happens for various reasons, and a few of them are listed below:


  • Network Issues/Technical Issues: When there is a network or technical issue, your phone service provider fails to recognize the caller.
  • International Calls: If someone is trying to reach you from a foreign country, you may receive an unknown label while receiving a call. Your service provider can’t identify the caller due to the difference in the telecommunication system.
  • System Limitations: If there are system limitations, your service provider will fail to acknowledge the caller trying to contact you.

What is “No Caller ID”?

When you see a “No Caller ID” labeled call on your screen, the caller doesn’t want you to know whose number it is.


The “No Caller ID” label suggests you are getting a call from someone who has intentionally hidden their identity.


Some reasons that you are receiving a “No Caller ID” can be:


  • The callers deliberately block their information as they might be stalkers, frauds, and scammers. 
  • Another reason callers hide their identities is the nature of their work. Some business companies and individuals lock up their phone numbers to restrict return calls.

Differences Between Unknown Caller and No Caller ID

“Unknown Caller” occurs when the phone carrier cannot identify the caller, often due to technical issues, network constraints, or international calling protocols. Conversely, “No Caller ID” appears when the caller deliberately. The table below better shows the difference between no Caller ID and Unknown Caller.


Unknown Caller

No Caller ID

The phone carrier fails to identify the caller’s details.The caller is intentionally hiding their information.
These calls often arise from technical/network issues, system limitations, and foreign calls.These calls happen if the caller deliberately masks their ID.
It is common among different service providers or countries.It is primarily practiced in the business field and personal privacy situations.
These can be harmless as one might be waiting for a call from a legitimate source. These calls are doubtful as there is a possibility of getting scammed.
Unknown callers can be easily tracked, and legal action can be taken if found involved in any illegal activities.No caller ID cannot be tracked easily, allowing users to get away without facing legal consequences if they are engaged in illegal activities.

Can You Identify No Caller ID and Unknown Callers?

Identifying callers who use “No Caller ID” or appear as “Unknown” can be challenging, as these features are often used to maintain anonymity. However, there are a few methods to identify unknown callers.


  • Dialing *69 reveals the number of the last person who called you, even if it’s an unknown number.
  • If *69 doesn’t work, contact your phone service provider and ask them to access call detail records (CDRs) to find out more about the caller.
  • Several apps like Truecaller offer reverse phone lookup services. Whenever you receive an unknown call, the app shows the number, and sometimes, the caller’s name.
  • If you suspect that the call was a scam, you can report it to the Federal Trade Commission (FTC). They investigate and identify callers who mask their IDs to commit fraud.

How To Block “Unknown” and “No Caller ID” Calls?

Receiving “Unknown” and “No Caller ID” calls frequently can be quite frustrating. You can block such calls on your phone.

Block/Silence Unknown Calls On iPhone

Unfortunately, if you are an iPhone user, you cannot completely block “Unknown” and “No Caller ID” unless you use third-party applications.


However, one special feature on the iPhone helps you to silence unwanted calls. Follow the steps below to silence unknown calls on your iPhone.


  1. Go to the “Settings”.
  2. Select the “Phones” option.
  3. Select the “Silence Unknown Callers” option.
  4. Slide the toggle to the right.


When you enable “Silence Unknown Callers” on your iOS device, it automatically blocks all the unsaved numbers. Check your voice messages and missed call lists to stay informed about such calls.

Block Unknown Calls On Android Phone

Android Users can easily block unwanted calls that they are getting continuously. To block “Unknown” or “No Caller ID” calls, follow the steps below:


  1. Go to your “Phone” application.
  2. Tap on the three vertical dots on your screen’s top right side.
  3. Select the “Settings” option.
  4. Click on the “Block Numbers” options.
  5. Turn on the “Block Unknown/Private Caller” option.

When dealing with “Unknown” and “No Caller ID” calls, Calilio can significantly enhance your experience. Beyond call blocking, our cloud phone system comes with caller ID, and call screening features which allow you to understand who is calling before you answer. Sign up today to identify and manage calls efficiently.

Frequently Asked Questions

How do I find out the number of a No Caller ID?

Dial *69 immediately after the call to find out and call back the last caller. You can also use third-party apps like Truecaller to identify the number of a No Caller ID.

Does no caller ID mean you have them as a contact?

Receiving a No Caller ID call does not mean the caller is in your contacts. It simply means the caller has blocked their number from appearing on caller ID, regardless of whether they are in your contact list.

Is no caller ID someone I blocked?

Receiving a No Caller ID call does not necessarily mean the caller is someone you blocked. It indicates that the caller has used privacy settings to hide their number from appearing on your phone.

Can no caller ID be traced?

Tracing a No Caller ID call is challenging because the caller has hidden their number. However, you can dial *69 to see if you can call them back.

Can you call back a No Caller ID?

Directly calling back a No Caller ID is not typically possible since the number is hidden. However, you can use *69 to call back the last number that called you.

What happens when you call someone with no caller ID?

When you call someone with your number set to no caller ID, your number will not appear on their phone. Instead, they’ll see labels like “No Caller ID,” or “Private.” Many people choose not to answer these calls due to concerns over spam or privacy.

What is the difference between Unknown Caller and Private Caller?

An “Unknown Caller” typically appears when technical issues prevent the caller’s number from being identified by your network, often due to international calling or system limitations. A “Private Caller” or “No Caller ID” appears when the caller has intentionally blocked their number to hide their identity.

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