What is a hosted PBX?

First, what is a PBX?

Before you can understand a hosted PBX, it helps to be clear on the PBX part. PBX stands for Private Branch Exchange, and despite the old-fashioned name the idea is simple: it is the system that runs a business's internal phone network. It gives each member of staff their own extension, routes incoming calls to the right person or team, lets people transfer calls between one another, takes voicemail when no one picks up, and connects the whole business to the outside telephone network.

For decades a PBX was a literal piece of equipment, a box sitting in a comms room or cupboard that your business owned and looked after. Every phone in the building wired back to it. That box is what people pictured when they said "the phone system". The PBX still does the same job today; what has changed is where it lives.

So what makes it a hosted PBX?

A hosted PBX is exactly that same phone system, but it runs in your provider's cloud rather than on hardware at your site. "Hosted" means someone else hosts it for you, on their servers, and you reach it over the internet. There is no box to install, nothing to power and nothing to maintain in your building. Your team connects to it from a mobile app, a web softphone in the browser, or an IP desk phone, and the system itself sits safely in the cloud.

This is the same thing people mean by a cloud PBX or a cloud phone system; the words are interchangeable. The practical upshot is that the provider runs and updates the platform behind the scenes, while you manage your own setup, your numbers, your users and your routing, from a simple web portal. You get all the power of a business phone system without ever touching a server.

What can a hosted PBX do?

A hosted PBX does everything a traditional PBX did, and a good deal more, because it is built on modern internet technology. At its heart it gives every person an extension and routes calls between them, but the day-to-day value comes from the features layered on top. These are the things that make a small team sound and behave like a far bigger one.

An auto-attendant, sometimes called an IVR, greets callers and directs them to the right department, so a single number can reach your whole business. Ring groups let a call ring several people at once, or in turn, so it gets answered quickly rather than landing on one busy line. Voicemail takes a message when no one is free and emails it straight to you, and call recording keeps a copy of conversations for training, quality or compliance. All of it is set up and changed from the portal, in minutes, with no engineer and no new hardware.

Hosted PBX vs on-premise PBX

The clearest way to understand a hosted PBX is to compare it with the older on-premise model, where you buy and run the box yourself. The differences are not subtle, and they are the reason most businesses have moved, or are moving, to hosted. The table below lays them out side by side.

Read down the right-hand column and the case for on-premise is essentially "you own the box". That ownership matters to a small number of very large or specialist organisations, but for the vast majority of UK small and medium businesses the hosted model wins on every practical measure. If you want the full comparison, including cost over three to five years, see our guide to hosted VoIP vs on-premise PBX. And if you are already running an old system, our guide to moving from an on-premise PBX to the cloud walks through how the change works in practice.

Why it matters now: the 2027 switch-off

There is a deadline that makes this more than a matter of preference. The UK's old PSTN and ISDN networks, the traditional copper lines that on-premise phone systems have relied on for decades, are being switched off on 31 January 2027. After that date, any phone system still connected over those lines simply stops working, and businesses still running one will need to move to internet-based calling or replace it entirely.

A hosted PBX sidesteps the whole problem, because it already runs over the internet by design. There is no copper line to lose, no hardware to migrate and no last-minute scramble. Moving to a hosted PBX lets you meet the 2027 requirement and modernise your phone system in a single step, on your own timetable rather than against the clock. Our guide to the PSTN switch-off in 2027 explains the deadline in full and what it means for your business.

Where Voxora fits

Voxora is a cloud phone system for UK small and medium businesses: a modern hosted PBX delivered as a complete service. You get the extensions, auto-attendant, ring groups, voicemail and call recording described above, ready to go live in minutes, with your number kept and real UK support behind it. There is no box to install and nothing to maintain, because the platform runs in the cloud and we look after it.

The phone system is the core of what we do, and it sits within a wider cloud communications platform, so as your business grows the same foundation extends to more ways of reaching and helping your customers. If you have been weighing up what a hosted PBX is and whether it is right for you, the honest answer is that for most UK businesses it is now the natural choice, and getting started is genuinely a matter of minutes rather than weeks.