12 Free PBX business solutions

Adopting an existing VOIP service from the top PBX providers is a suitable solution for many companies. But it is not an easy job to find the right one.

Providers are constantly trying to fit the needs of every customer individually. Finding the right solution for every use case might be almost impossible, considering the team size, required features, and security issues. 

Companies can try out open-source solutions or platforms for all those cases when a service does not fit their expectations and requirements. 

Are there free PBX solutions? Yes, there are. These are open-source PBX software solutions. Necessary hardware needs to be provided, which is a suitable computer.

Any business can develop and tailor in-house PBX applications using free PBX software. The source code is available online and can be tailored for every specific scenario.



Asterisk is “the father” of all open-source PBX and VOIP solutions. It is the leading open-source telephony platform, with enormous feature lists that continue to grow. 

The Asterisk toolkit is used by a mass quantity of developers around the world. Many of the suppliers on this PBX list have either begun with or are based completely on the Asterisk project.

It is packed with the standard PBX VOIP features. They consist of an automatic telephone, an interactive voice response menu, conference calling, and voicemail. 

The Asterisk makes it easy to turn any computer into a PBX. 

As a popular platform, Asterisk provides web classes and tutorials to help users do their job with the platform.


Compared to the other free solutions on this list, VitalPBX is rather new. And while the first version was released in early 2018, they have worked hard and now offer a well-developed feature-rich product.

The VitalPBX platform can be installed on physical hardware or the cloud. It is essentially a Linux-based Graphical User Interface for Asterisk, and as such, it can be run with minimal effort. The interface is well structured, and its features are easy to find and use.

VitalPBX is free to use, and a professional support package and add-ons are paid options.


SIP Foundry provides many of the solutions that the Asterisk engine can power. You can construct your own voice and video communications with SIPFoundry. Also, it supports conference calls, messaging, and chat. Like Asterisk, the platform includes everything you might need to build your PBX solution.

While Asterisk is 100% free and open-source, SIPFoundry has a somewhat different spin. It offers professional paid assistance to developers based on customer needs. It might seem like excess income, but adopting a support team might be essential for some businesses looking to build their system. With a focus on the marketplace, the tool is free for commercial or private use. 

This project has features from the HylaFAX, FreePBX, Openfire, and Postfix open-source projects.


Elastix, as a standalone project, is no longer actively maintained or developed.

Currently, Elastix is owned by 3CX  and can be found in 2 versions (OLD and NEW). The old one is still preferred by many but lacks security as it has been discontinued since 2016 and gets no security updates. The new version is just the Linux version of 3CX now.


Issabel is the unofficial successor of the old Elastix. It offers way better security and frequent patches. The platform is much better looking and feeling, and they have spent a good amount of time cleaning it. 

The platform is free. It is open-source, and there are not many pricing options or catches. The support is paid, and there are a few paid add-ons. The source code can be freely downloaded from SourceForge or GitHub.

Issabel uses addons that help satisfy almost every need. Lately, they have also worked hard on their API so that you can expect a lot more than the old Elastix.

That being said, we must mention that there is almost no documentation on Issabel and half of the available information is in forums making it hard to find. The other half of the information is sadly in Spanish.


Free SWITCH was also based on the Asterisk platform and was created and developed by three of the original programmers of the Asterisk platform. Anthony Minessale II, Brian West, and Michael Jerris.

FreeSWITCH is focused on modulators, cross-platform service, availability, and stability. 

It provides one of the most flexible platforms to construct your UC package. FreeSWITCH supports SIP, H.323, and WebRTC to leverage the latest technological advancements. 

It can integrate and interface with some of the other open-source PBX platforms. For less complexity, FreeSWITCH utilizes open software libraries that perform essential functions. FreeSWITCH delivers the calling features and some extras, such as speech recognition. It also offers PSTN ports for digital and analog circuits.


PBXInAFlash’s main feature is setting up your own PBX server quickly. The project has everything needed to set up a PBX system in less than an hour. 

It uses CentOS, an integrated Apache web server, a SendMail server, MySQL database, firewalls, and all essential protocols. 

Users can pick from dozens of add-ons to tailor the system. Backups, Caller ID lookup services, SSL keys, Google Voice integration, and fax support, to name a few. PBXInAFlash seems to be the easiest and quickest solution to adopt.


FreePBX combines the best of both worlds and leverages the work. The project uses the Asterisk system. This is the most recommended free PBX for new users.

Users may download either just the GUI or the whole package. It consists of a pre-configured OS, Asterisk, and the FreePBX GUI. So while adopting Asterisk may require some knowledge to take advantage of or to create your GUI, FreePBX brings it all together. FreePBX makes it feasible to establish your SIP Trunks that are part of the platform thanks to the integration. FreePBX also contains a long list of commercial modules and add-ons to enhance your system with even more features.


With OpenSIPs, it is easy to set up your own PBX. It focuses on the open-source implementation of a SIP server. The platform supports video, voice, IM, and presence services. It uses a modular design, scalable and very much customizable. 

OpenSIPs offers enterprise-class SIP server solutions and a very fast one at that. OpenSIPs has listed benchmarks and performance tests to support its claim. 

OpenSIPs often record webinars and make in-depth manuals for configuration similar to Asterisk.

A web interface makes it easy to collect data and shows on-the-fly configurations.


Bitrix24 offers its free virtual and PBX solutions to small businesses. And it comes with quite a lot of free and handy business tools. Their PBX is also based on VoxImplant, which is a good sign. Keep in mind that there might be some small fees and taxes involved when adding phone numbers.

Bitrix24 is not focusing mainly on the VoIP or PBX market and is trying to sell you its customer relationship management (CRM) software along the way. If it were not for that, we would have highly recommended them.


Kamailio is an open-source project with 15 years of constructive development. The original company left the project, but it continues to expand. Both the SIP server and Kamailio project continue to be built.

It features UDP asynchronous TCP and, SCTP, TLS to ensure secure communication. VoIP data consisting of voice video and text, and even WebRTC support is also present. Kamailio also supports instant messaging, least-cost routing, load balancing, and routing failover. 

With authentication and authorization for enhanced security and a high level of encryption, Kamailio offers the strongest level of security on this list. It makes it a good recommendation for any staff or business that needs to keep everything locked down and protected. As a result, Kamailio may be a bit more challenging to adopt.


The 3CX Phone System is the last open-source PBX based on the SIP standard. This solution allows extensions to make calls on the PSTN or standard services. 

The platform also offers an easy-to-understand web-based GUI. The setup process is simple – an executable file. 

3CX supports iOS and Android for mobile customers. Windows and Mac softphones are supported, too. It appears to take out the hassle of development required to establish your own PBX server. WebRTC adoption makes web conferencing possible. Click2Call and CRM are also part of the features. 

Like the rest, an internet training academy is available for users to understand how to manage the platform.

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