Insights and Resources • Last Updated 8/25/2023

What is a VoIP number, and how do they work?

Learn about the advantages and flexibility of VoIP numbers, and get started with your own number today.


By Fiona McDonnell

Dialing a VoIP number

What’s A VoIP Number

In simple terms, a VoIP number is a phone number that connects over the internet, rather than traditional phone networks.

VoIP numbers look just like standard phone numbers, but offer far more flexibility than their standard counterparts. The reason being, the same VoIP number can be used on multiple devices, so long as you have an internet connection.

Who Uses VoIP Numbers?

Since VoIP numbers are assigned to a user, rather than a specific device, VoIP phone numbers are especially useful for large and small businesses, because calls to a single VoIP number can ring through on several devices. Additionally, VoIP numbers are not confined to a particular physical location.

So VoIP numbers are ideal for organizations that need phone numbers which are not restricted to a specific telephone, in a single location.

  • Small Businesses. VoIP phone numbers are excellent for small businesses that need the ability to take calls from anywhere (be it any room in the building or multiple business locations) at the most minimal cost.
  • Enterprise Businesses. VoIP numbers make life easier for enterprises that need many phones and phone numbers, since VoIP numbers can be configured and assigned to devices from a central control panel.
  • Call Centers and Managed Service Providers (MSP). Any business that needs a large inventory of phone numbers that can be quickly and easily assigned to a different device or user—clients, call center representatives, or anyone else—will find that VoIP numbers are the most cost efficient option.

How VoIP Numbers Work

Traditional phone numbers transmit analog audio over legacy public switched telephone networks (PSTN).

Conversely, when you make a call using a VoIP phone number, the VoIP device or VoIP provider converts the analog audio into a digital signal, which is transmitted over the internet. The audio data is converted back into an audio signal when it reaches its destination.

Sending the audio as data over the internet is what enables you to make phone calls from computers, smartphones, VoIP phones, and traditional phones with VoIP adapters. And you can make a phone call from a VoIP phone number using any internet connection, even a cellular or wifi internet connection.

If you want a VoIP phone number, the easiest way to get one is to sign up for service with a VoIP provider. They’ll assign you a VoIP phone number as part of your service package.

If you already have a traditional phone number, a VoIP provider can easily use your existing phone number as your VoIP phone number. So you don’t even have to change your phone number to get a VoIP number.

In short, getting a VoIP phone number is essentially the same as getting a traditional phone number, so long as the phone service provider you choose is a VoIP provider.

There are significant technical differences between traditional phone numbers and VoIP phone numbers.

However, in terms of the call experience, traditional phone numbers and VoIP phone numbers are the same. You won’t be able to tell the difference between making a call from a traditional phone number and calling from a VoIP phone number.

International VoIP Numbers

VoIP numbers are relatively easy to create and assign to a device. Therefore, it’s relatively easy to get VoIP phone numbers that are formatted for any country.

However, all phone numbers—VoIP or otherwise—are subject to regulations and network limitations. So it’s important to check your VoIP service provider’s coverage to make sure that they have numbers available for the country or countries you need before you sign on.

Additionally, some countries have regulations that make it difficult to use VoIP phone numbers for calls to or from those countries. The quality of a country’s internet infrastructure also impacts how usable VoIP numbers are in those countries.

Countries with VoIP restrictions

These are the countries with reported complications to using VoIP phone numbers (regulations or communications infrastructure limitations):

  • Belize
  • Brazil
  • Caribbean Region
  • China
  • Cuba
  • Egypt
  • Iran
  • Jordan
  • Libya
  • Mexico
  • Pakistan
  • South Korea
  • North Korea
  • Kuwait
  • United Arab Emirates
  • Oman
  • Morocco
  • Paraguay
  • Israel
  • Qatar

It’s true that some countries restrict VoIP numbers because they’re easy to spoof. But just because there are known challenges to using VoIP numbers in a country doesn’t necessarily mean that you cannot use VoIP numbers in that country. It just means there may be some restrictions.

For example, in China, VoIP numbers are only permitted on the China Unicom and China Telecom networks. If your VoIP provider partners with those Chinese providers, you may be able to use your VoIP numbers for calls to and from China.

If you’re concerned about whether or not your calls may be blocked in a country that you need to call to or from with your VoIP number, ask your VoIP provider. They may be able to connect your calls in that country.

Reverse Lookups for VoIP Numbers

It’s possible to do a reverse VoIP phone number lookup to find out if a phone number is a VoIP number and get carrier information about a phone number. However, it’s worth knowing that this information is usually not free, since getting access to phone data is expensive and challenging for data providers. But a reverse VoIP phone number lookup is the only way to be truly sure if a phone number is a VoIP phone number or not. The caller ID name (CNAM) and even the phone number itself that displays on your caller ID can be manipulated. So it’s impossible to distinguish between a traditional phone number and a VoIP phone number simply by seeing the number.

Blocking VoIP Numbers

As we mentioned earlier, VoIP numbers can easily be faked. It’s also simple to assign a new VoIP number to a device. So scammers often use VoIP numbers for scam calls. That means that you may want to block a VoIP number or three.

The good news is that blocking a VoIP phone number is the same as blocking a traditional phone number.

The only struggle with blocking VoIP numbers is that blocking a VoIP number only blocks that VoIP number. It does not block calls from the device that was making the spam calls. A spam caller could change the VoIP phone number assigned to the phone he’s using, and you’d have to block that new number.

Common VoIP Number Questions

Can VoIP Numbers Receive Texts (SMS/MMS)?

Yes, VoIP phone numbers are capable of receiving SMS and MMS messages. In fact, most smartphones are equipped to send and receive text messages using VoIP phone numbers without downloading any additional apps or software.

Do Scammers Use VoIP Numbers?

Unfortunately, yes. VoIP phone numbers are relatively easy to fake. And the caller ID information can be easily manipulated. So VoIP numbers are the preferred type of phone number for scammers and robocalls.

Are VoIP Numbers Traceable?

VoIP phone numbers are technically traceable. But it’s very challenging, because a VoIP number can be quickly assigned to a different device. It won’t tell you exactly where a phone call is coming from, but you can use a reverse phone number lookup to find out who owns a VoIP phone number.

Yes. Even in countries where VoIP numbers are blocked, it’s often not illegal to provision a VoIP number. The local providers simply won’t connect calls from VoIP numbers. But check your local regulations if you’re concerned about the legality of VoIP numbers.

What’s A Non-VoIP Number?

A non-VoIP number is simply a traditional phone number that connects through the public switched telephone network (PSTN). Traditional phone numbers are assigned to a specific device, most often a landline telephone.

Contact our team of experts to learn what makes Telnyx the best VoIP provider.

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