CNAM (Caller ID Name)

What Is CNAM (Caller ID Name)?

CNAM is a technology that allows phone numbers to be linked to other alphanumeric data that displays on Caller ID systems. It can be used both to help prevent fraud and to help perpetuate it.

CNAM stands for Caller Name Delivery but is also regularly referred to as Caller ID Name and sometimes Caller Name Presentation (CNAP). CNAM determines the information displayed as the caller ID when phone calls are made or received.

While CNAM’s availability is specific to the USA and parts of Canada, its listed data is are supported by database lookup services online, such as SEON’s phone API. The Canadian system works slightly differently from the US, as described in detail below.

CNAM names allow for the use of 15 alphanumeric characters. They are always uppercase, and no use of punctuation (beyond spaces) is permitted.

How Does CNAM Work? 

CNAM works only in the US, as follows:

1. In the USA, phone carriers issuing telephone numbers to businesses have the ability to feed in CNAM details that link to each number.
2. Companies and end users can specify the CNAM details they want. However, they do not have the ability to change CNAM data themselves directly. Usually, this is handled as a support request that must be actioned by their phone carrier.
3. Phone carriers share CNAM details with a number of CNAM database providers. There are around eight of these in the US: some are private companies, and others are Incumbent Local Exchange Providers (ILECs) or Competitive Local Exchange Carriers (CLECs).
4. When calls are made, it’s down to the terminating carrier – namely, the carrier operating the line being called – to perform a CNAM lookup on the incoming number. Again, this makes use of the databases operated by the CNAM database providers. Terminating carriers are charged a nominal fee for each lookup, known as a CNAM dip. The fee for the provider is usually in the region of 0.002 to 0.006 cents.
5. The carrier displays the CNAM information on the end-user’s caller ID system when a call is coming in.

CNAM works differently in Canada, where there are no centralized databases and no lookup dips. On the Canadian system, CNAM values can be set on each company’s own telephone PBX (Private Branch Exchange) systems. They are also passed directly through to the receiving line.

Where Is CNAM Available?

CNAM is specific to the USA, with a similar system available in parts of Canada. It is, however, supported by many online database checking systems, such as SEON’s reverse phone lookup which offers global coverage for Caller ID Name.

On top of this, some telecom providers in other parts of the world have an infrastructure that allows alphanumeric CNAM details to show up on calls from the USA.

Nevertheless, this functionality can vary. In some cases, only the phone number will show. In other situations, no caller ID is passed at all.

Is CNAM Lookup Available Internationally?

Automatic CNAM lookup isn’t natively supported outside the US. It’s part of the fixed-line telephone system in the US and Canada only.

However, as discussed above, many online services (often free ones), facilitate CNAM database lookups. It’s therefore possible to manually input a US telephone number – from anywhere including the UK – and view its associated CNAM record. This can prove useful in situations when somebody needs to verify that a number is related to the company it claims to be.

Who Updates the CNAM Databases?

The data in the CNAM databases ultimately originates from US telephone carriers, who submit the information to the database providers. While the providers themselves work to keep the data accurate and current, they depend on accurate data flowing from the carriers.

The system is not foolproof, and it’s certainly not perfect. Telephone service providers don’t tend to notify every database provider of their CNAM details and changes. Similarly, each carrier tends to choose a specific database provider to use to perform their lookup dips. This is similar to the situation when financial service providers make use of multiple credit reference agencies.

As such, the possibility exists for errors and outdated information. Hackers and cybercriminals also work hard to work around and spoof CNAM details in order to impersonate legitimate companies.

How Many CNAM Databases Exist?

There are approximately eight active CNAM (or Line Information) databases in active use across the US.

Operators include:

• Baby Bells
• Qwest
• Sprint
• Intelco
• Verisign

Increasingly, there are ecommerce software companies that offer alternative lookup options to CNAM or provide lookup services that incorporate CNAM data alongside other information. A popular option is to also provide information based on Open Source Intelligence (OSINT) gleaned from publicly available information and social media sites.

Types of CNAM

It’s important to note that incoming and outgoing CNAM in the US doesn’t all use one linked system – unlike the Canadian implementation, which does work along those lines.

In the US, the differences are:

Incoming	Outgoing
The terminating carrier sources incoming CNAM data via a lookup dip in one or more CNAM databases. When a call comes in, the carrier references the incoming number with the database(s). The Caller ID system displays the resulting CNAM value on the recipient’s phone.	Outgoing CNAM data is managed by the provider that owns each number.  Companies using the numbers request their desired CNAM information via their provider. In turn, the carrier submits this data to the database providers.

Why Is CNAM Important?

CNAM is important both to companies and to consumers, for reasons of trust and safety, including fraud prevention. Studies suggest that 75% of people will no longer answer phone calls from companies and numbers they do not recognise.

CNAM can help consumers avoid phishing and scam calls and give them confidence that they’re speaking to a legitimate business. In turn, businesses can help customers help themselves. For example, they can communicate what their CNAM value should be on incoming calls.

What Is the Difference Between Caller ID and CNAM?

Caller ID and CNAM are linked technologies, but they’re not the same thing.

CNAM is a lookup facility that cross-references US and Canadian phone numbers with alphanumeric values – typically displaying the company name the number is associated with.

Caller ID is a global system, which uses technology to display the phone number an incoming call is being made from. Caller ID can be used to display a CNAM value, but it’s a separate system.

How Does CNAM Fight Fraud?

In fraud prevention, CNAM data is used as one of several sources of information that can help assess whether a person or a transaction is likely to be fraudulent. It can be a tool to fight synthetic identity fraud or other less sophisticated methods to hide a real identity.

In general terms, CNAM can help fight fraud in two key ways:

1. It helps companies to give their customers confidence that they are talking to a genuine representative and not a fraudster.
2. It gives consumers, via Caller ID displays and manual lookups, the ability to check who a phone number is registered to.

However, it’s crucial to understand that CNAM is vulnerable to fraud and inaccuracy. It can offer one extra tool to fight fraud, but only alongside a comprehensive set of other precautions. The spoofing of CNAM data can present a fraud risk all of its own.