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How to Find a Phone Number's Owner if It's VoIP Call?

March 31st, 2021 by William Wentowski

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VoIP phones have become the norm for businesses everywhere. The convenience they provide with allowing calls to anyone in the world over the internet simply can't be beaten. However, there is a common concern when utilizing VoIP for calls. How can you trace unidentified numbers to their owners?

When unidentified callers call you through VoIP, you only get to see their caller ID. This lack of information given can make it challenging to figure out who may be calling your office phones. Is it a client or some spam caller who somehow got your number? Thus, creating the issue of having to trace the number to the owner to figure out how to handle it. Thankfully, there are different ways to trace the owner of a number when it comes to VoIP calls.

VoIP Service Provider

One way to find the owner of an unidentified VoIP number is through the VoIP service provider. All you need to do is note down the caller ID and the time the call was made. Then, contact your VoIP service provider and provide the necessary information. They will be able to track the owner of that number for you. However, there is one problem with this method. The caller that you are trying to find must have a registered caller ID or IP address that they are using for the calls. If they used a third party or fake IP to make the call, it's harder to track them.

Reverse Phone Detective

This method utilizes the different apps available online to trace the owner registered to the phone line. There are numerous reverse phone detectives available online, and most are free. Usually only requiring you to input the caller ID in the search engine to produce the owner in few seconds. Online reverse searches aren't just limited to VoIP. You can also trace landline calls that only display a number with them as well.

Using Hardphone or Softphone Packet Analyzers

When connected with a proxy or server and using a Session Initiation Protocol (SIP) hardphone or softphone, there is a way of tracing a VoIP number with a packet analyzer. It just depends on how you are connected; via proxy or server.


For hardphones, use the packet analyzer on your local router or server to filter for both hard phone IP and SIP. If you have access to an Internet Telephony Service Provider (ITSP) Server, you can instead trace the number yourself by downloading a Secure Shell (SSH) client and running a trace command.


Softphones require the installation of a packet analyzer (such as Wireshark) onto the device. These allow you to apply a SIP filter on your calls. To properly apply the filter, you need to choose the "FROM" field on the invite packet option. Setting this up will show you the IP details of where the call originated, such as their name.

Setting Your Device to Display VoIP CallerID Name

Tracing the owner of a VoIP number becomes easier when you have the original number. However, most systems don't display the entire number. VoIP numbers consist of two different parts:

  1. The first is the caller ID which is the number you can see all the time with regular calls.
  2. The second is the caller ID name (CNAM) which most phone terminals don't display.

In order to get the full number, you have to change the configuration of your phone to display both the ID name and the CNAM.

Luckily, there are numerous websites such as CallerID.com that provide the step-by-step process to configure your device to show the full number. They show you how to set up an external query to add it to the database, which updates your phone to show both the ID name and the CNAM. The type of query can be system-related (SIP/SS7, etc.) or could be a Json/Ajax type. For those with programming skills, implementing a query for said number wouldn't be difficult to do. Once implemented, there would be a return on caller ID names as long as they are in the database.

Using The VoIP Address Domain

A VoIP Address usually comes in one of these formats: 1234@voip.domain.tld, 5678@sample.com, 1234@176.42.127, etc. All incoming calls are logged in to your phone. Either as the mapped number or the VoIP address as displayed above. With the domain name, you can easily trace the IP address provided back to the number that originally called you.

Ultimately you can trace any call, but how you can go about it varies. It ultimately depends on what you have access to, and now you have a better understanding of what is available to use. You have all the methods we mentioned above, but remember if it's a serious situation the authorities can use other means to trace these calls.

Contact us if you have any additional questions.

Posted in: VoIP

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