Traditional PBX vs VoIP: Cost, Reliability & More

A phone system is essential for almost every organisation, whether that’s a charity, business or local authority. Broadly speaking, there are two options to provide that essential system – a traditional PBX or the more modern VoIP.

In this post, we’ll take a closer look at the two options and explore which is best for your organisation.

Traditional PBX vs VoIP – the basics

First and foremost, let’s look at the fundamental differences between PBX and VoIP.

What is a traditional PBX?

PBX stands for private branch exchange. It refers to an on-premises phone system that is connected to your building’s landline. PBX systems share many characteristics with standard landlines in that their location is fixed, and they use the traditional means of making calls.

The main difference between a PBX and a single landline is that several people can use it. PBX systems switch calls between users on the same landlines, meaning there’s no need to have a landline for each user. Calls can be made internally within the PBX system or externally where landlines are essentially shared or ‘trunked’.

What is VoIP?

On the other hand, VoIP is a much newer system that uses your existing internet connection to make calls. Short for Voice over Internet Protocol, it eliminates the need for a landline with devices that connect directly to the internet – either through an ethernet cable or with a wireless connection.

VoIP devices work much the same as traditional PBX phones. Calls can be switched, held, recorded and much more, both internally and externally. As a result, many end-users would be unaware that they were using a VoIP phone rather than a PBX when making calls.

PBX vs VoIP – reliability

If you’re deciding between traditional PBX and VoIP, the first factor should always be reliability. After all, if your phone system isn’t reliable, you won’t be able to make and receive some of your calls – defeating the primary purpose altogether.

Given that traditional PBX has been around for several decades – since the 1970s, in fact – it’s well established that it is a reliable system. Thankfully, over the past decade, VoIP has developed the same reputation.

Because calls are made and received through your internet connection, reliable VoIP simply requires reliable broadband. With the days of dial-up long behind us, reliable broadband is pretty much universal for organisations across the UK.

What about quality?

Much like reliability, the quality of VoIP has advanced with the expansion of broadband. To make high-quality calls, users simply need a bandwidth of 100kbps or 0.1mbps. That increases based on the number of users, with 1000kbps or 1mbps for 10 VoIP handsets used at the same time, for example.

Given that the average UK broadband speed is now 64mbps – enough for 640 callers – there’s nothing stopping VoIP calls from having crisp, clear quality. With broadband speeds continuing to increase, many VoIP users may actually experience better quality than they would on a traditional PBX, which provides the standard quality of landline calls, as it has done for several years.

Comparing the costs

When you’re choosing between two options that provide essentially the same function, it’s only natural that costs will come into play. So how do VoIP and PBX compare?

Firstly, PBX systems are a significant investment for any organisation. To connect each user to the PBX board, their phone needs to be wired in. Naturally, this means the costs can rise significantly based on the number of users. Once the system is installed, the cost of calls depends on your provider, with international calls typically quite expensive.

Because they connect directly to your existing broadband connection, VoIP phones are much simpler and less expensive to install. The cost will still rise per user based on the number of devices needed, but that will be nothing compared to the price of wiring in new users. Also, bear in mind that you don’t actually have to take a desk phone for VoIP. Now an app on your smartphone or desktop is enough – potentially reducing costs further.

In the long run, VoIP could also continue to save you money as the cost per call is typically lower than that with a traditional PBX and landline. That’s especially true with international calls, which don’t see such a dramatic rise with VoIP compared to PBX.

Worlds apart for flexibility

While VoIP matches PBX for quality and reliability and has the edge when it comes to cost, one area where the two are truly worlds apart is flexibility. PBX systems are wired to your landline, meaning their location is fixed, so you can only make and receive calls from your office.

If you want to make calls from home or a temporary workspace, you’ll need to use your mobile or an alternative landline. The result is an unprofessional look for your organisation, paired with a lower quality of calls. It also means you can’t use all PBX features like call switching you have in the office.

In stark contrast, VoIP provides office-calling functionality wherever you’re based. With devices working anywhere with a stable internet connection, you can set up your VoIP phone at home, on-site or simply in your normal office. Whatever the case, you’ll get full functionality so you can still work as part of your team.

This has become particularly valuable following the coronavirus outbreak in 2020, which saw as many as 60% of UK staff forced to work from home. While initially disruptive – especially for those without VoIP – it allowed employees and employers to experience the cost savings and better work-life balance of home-working. In turn, that’s led to more organisations offering remote or hybrid working on a permanent basis.

Traditional PBX vs VoIP – the verdict

When comparing VoIP and PBX, there’s only one winner. With broadband now universally fast enough to facilitate high-quality VoIP calling, any issues with reliability and quality have become a thing of the past. Organisations can now get the best of both worlds, with reliable, high quality calling combined with lower costs and better flexibility.

The benefits of VoIP for businesses, charities and third-sector organisations

As explored above, unrivalled speed, reliability and call quality make VoIP the clear winner when it comes to performance. But how exactly does PBX vs VoIP compare when it comes to meeting the unique communication needs of businesses, charities and third-sector organisations?

VoIP for businesses

Cost efficiency: Cost-efficient investments are a top priority for businesses. Instead of relying on traditional phone systems that come with sky-high bills, VoIP leverages the internet to transmit voice data. This significantly reduces communication costs and is particularly advantageous for businesses with high call volumes, or those making long-distance or international calls.

Enhanced mobility: Modern businesses no longer confine employees to traditional office spaces. Hybrid and remote work are becoming increasingly popular in the UK and VoIP provides businesses with the flexibility to support these models. Whether teams are working onsite, remotely or on the go, VoIP promises seamless communication from anywhere with a reliable internet connection.

Advanced collaboration features: How does PBX vs VoIP compare when it comes to collaboration? VoIP goes beyond voice-based phone calls and introduces advanced features like audio conferencing and screen sharing. These features support real-time communication and make it easier for teams to collaborate, innovate and manage projects.

Scalability to support growth: Scalability is crucial for growing businesses and VoIP systems can easily adapt to accommodate changing needs. This flexibility makes it easy to crown a winner in the PBX vs VoIP debate.

Secure and compliant communication: Regardless of size, security is paramount for businesses. VoIP prioritises security with advanced encryption features designed to keep communication confidential and compliant with data protection regulations.

VoIP for charities

Advocacy: Charities rely heavily on voice-based communication to engage with supporters. VoIP keeps lines open with an uninterrupted, high-speed service. For charities, this helps address the challenges posed by the cost-of-living crisis currently impacting individual giving.

Budget friendly: Most charities operate with limited financial resources which makes cost-efficient investments essential. Unlike PBX, VoIP strikes a balance between performance and affordability, making it a smart investment for charities.

Simplified infrastructure: VoIP pares back physical infrastructure and simplifies connectivity by integrating voice and data services. This streamlined approach makes maintenance and troubleshooting more straightforward, a major benefit for charities with limited technical expertise.

VoIP for third-sector organisations

Supports outreach: Similar to charities, third-sector organisations rely on outreach initiatives to connect with volunteers, supporters and stakeholders. The high-speed connectivity of VoIP supports these efforts and makes it easy to build and nurture meaningful relationships.

A focus on collaboration: Collaboration is key in the third sector and VoIP actively strengthens partnerships between team members, volunteers and stakeholders. As well as crystal-clear voice calls, benefits include features like video conferencing and cloud-based collaboration tools.

Sustainability: Vetoing physical phone lines not only unlocks cost benefits but reduces overall energy consumption. This makes the PBX vs VoIP decision easy for third-sector organisations seeking to align operations with broader goals of environmental responsibility.

From profit-forward businesses to growth-oriented charities and third-sector organisations, VoIP offers tailored benefits that address the unique communication needs of each sector. The technology not only enhances operational efficiency but helps give enterprises the competitive edge needed to thrive in today’s digital age.


If you would like to find out more about VoIP services for your organisation, don’t hesitate to get in touch with VS Group. As a dedicated provider of VoIP for the voluntary and business sector, we’re best placed to tailor our solutions to any unique requirements you have. Call us on 0330 094 0170, email or get a quote today.


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