Comparisons5 min read

What Is the Difference Between Caller ID and CNAM?

difference between caller id and cnam

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Are you often curious about who’s calling before you pick up the phone? Understanding the convenience of knowing not just the number but also the name behind the call distinguishes Caller ID and CNAM. These services are crucial in enhancing communication efficiency and helping individuals make informed decisions about answering calls.

What Is Caller ID?

Caller ID, known as Caller Identification, is a phone feature that displays the incoming caller’s phone number and sometimes their name before the call is answered. In the United States, caller ID comprises CLID (Caller ID number) and CNAM (Caller name). CLID is usually a 10-digit phone number associated with the call, while CNAM is a 15-character name.

Caller ID was introduced in the 1980s. It is used to screen calls and avoid unwanted telemarketing or spam calls. It utilizes caller identification technology and online databases to recognize and display information about the caller.

Caller ID has evolved from traditional landline systems to modern cloud-based business phone systems, providing users with valuable information about who calls them. While Caller ID is useful, it may occasionally provide inaccurate information.

What is CNAM?

CNAM, also called Caller Name or Caller Name Presentation, is a feature in telecommunication that displays the associated business or individual name of the caller on the receiver’s device. CNAM is primarily supported in the USA and Canada, providing more context than the basic Caller ID, which only shows the phone number.

CNAM only works for PSTN calls and does not work on toll-free numbers. It goes beyond the basic Caller ID service, which only shows the phone number - it provides additional context to the recipient about the person behind the call.

The records are maintained in a central database, and carriers must intentionally set the CNAM for each number. A business must inform its service provider to update the record if it changes its name. The update process can take up to two weeks, as the new information needs to propagate across all phone networks.

You must set up the CNAM correctly to maintain consistent caller ID information, especially when switching service providers or porting phone numbers. However, even with proper setup, there might be instances where the CNAM does not display consistently due to carrier practices or technical limitations.

Limitations of CNAM

Caller ID shows the caller’s phone number, enabling call recipients to recognize the caller before answering. In contrast, CNAM displays the associated name and provides additional caller identity information. However, these features may not always function seamlessly, leading to potential challenges in accurately displaying caller information.


  • Inaccurate or Missing Information: CNAM relies on databases that match phone numbers with corresponding names. It can display inaccurate or missing information, affecting the caller identification process.
  • Character Limitations: CNAM is often limited to displaying only 15 characters, including spaces. This constraint can result in the truncation of names or messages, impacting the clarity of information shown on the recipient's Caller ID.
  • Coverage Restrictions: CNAM identification is limited to calls terminating in the United States and parts of Canada. It reduces the global coverage of CNAM compared to Caller ID services like LCID (Local Caller ID).
  • Adaptation for Mobile Phones: CNAM technology was initially designed for landline phones and may require adaptations to work effectively with mobile devices. The process can sometimes lead to challenges in displaying CNAM information clearly on mobile Caller IDs.
  • Delay in Updates: Changes to CNAM listings can take up to 48 hours to reflect accurately. The delay can impact the timeliness and accuracy of caller identification for businesses and individuals.

Caller ID vs CNAM: Key Differences

The primary difference between Caller ID and CNAM is that Caller ID displays the caller’s phone number, while CNAM displays the name associated with the phone number, which is crucial to identifying the caller’s information, especially when the recipient may not recognize the phone number.

Caller ID is a feature that displays the caller’s phone number in the signaling information to set up the call. On the other hand, CNAM is a 15-digit alphanumeric string that identifies the caller by querying an authoritative database in the telephone network.


Caller ID


1. Telephone service that displays the caller’s number on the recipient’s phone, allowing the recipient to see the phone number of the caller before answering the call. 1. Displays the name associated with a phone number when a call is received.
2. The calling party determines it.2. The receiving carrier determines it.
3. It is a global system used to display the phone number of an incoming call.3. Automatic CNAM lookup is natively supported only in the US and Canada.
4. Recent updates like STIR/SHAKEN help ensure the authenticity of the originating caller's phone number.4. CNAM does not regulate the display of the caller’s name, and it can be used to enhance caller identification by providing the caller's name alongside their phone number.
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Caller ID and CNAM are two related but distinct technologies used in telecommunications for caller identification. The distinctions between Caller ID and CNAM are fundamental in understanding how incoming calls are identified and displayed to recipients, offering insights into the mechanisms behind call identification in telecommunication systems. 

While Caller ID is a standard feature in most telecommunications systems, CNAM is not always carried out when signaling a call. Instead, the terminating provider performs a lookup for the CNAM associated with a CLID by querying an authoritative database in the telephone network.

Frequently Asked Questions

How do I change my CNAM caller ID?

To change your CNAM caller ID, access your phone carrier’s settings or use a platform like DialMyCalls. In DialMyCalls, manage your CNAM entry within your account by selecting the desired caller ID. Ensure your recipient’s phone enables CNAM to display the updated information when you call.

Who controls CNAM?

CNAM databases are managed by specific companies that maintain pools of Caller ID Names. These entities update and store CNAM information tied to phone numbers, which may be displayed on devices receiving calls. Service providers access these databases to retrieve and display the related business name.

How do I disable CNAM?

Contact your phone service provider to request the deactivation of CNAM. Typically, providers can assist in turning off the CNAM display on outgoing calls. Disabling CNAM prevents the caller’s name from being shown alongside the phone number on the recipient’s device.

What is an example of a CNAM?

An example of CNAM is when a smartphone displays the name ‘John Smith’ alongside the phone number 555-987-6543 during an incoming call. CNAM enhances caller identification by providing the caller’s name, allowing recipients to recognize the caller before answering.

How do I turn on caller ID on my phone?

To turn on the Caller ID on your phone, open the Phone app, access settings, locate ‘Show My Caller ID,’ and toggle it on. It displays your phone number to recipients when making calls.

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