If you've ever wondered what actually happens when someone calls your company's main number and the call lands on the right desk, the answer is a PBX — a private branch exchange. A cloud PBX is the same thing, minus the box in the server cupboard. Here is what it does, what you need around it, and how it's usually priced.
What a PBX does
A PBX is the switchboard of a business. It sits between the public phone network and your team, and it decides where every call goes. The everyday jobs:
- Extensions: every person gets a short internal number, so colleagues can call each other for free and you can reach "142" instead of a mobile number.
- Routing: calls to your main number go to reception, a group of people, a voice menu ("press 1 for sales") or a queue — depending on the time of day.
- Voicemail, transfer, parking and conference calls: the basics that make a phone system feel professional.
- Reports and recording: who called, who answered, how long people waited.
For decades, all of that ran on hardware in your building, wired to copper phone lines.
What makes a PBX "cloud"
A cloud PBX runs the same software on servers in a data centre. Nothing changes for your callers. For you, three things change:
- No hardware to buy or maintain. The provider runs the servers, the backups and the software updates.
- Your team can work from anywhere. Phones and apps connect over the internet, so the office, home and a hotel room all work the same way.
- You pay per user. Instead of a large upfront purchase, you pay a monthly or yearly price for each person — and add or remove people as your team changes.
You'll also see the terms hosted PBX and cloud phone system. In practice they mean the same thing: a PBX that someone else hosts and runs for you.
What you need to run a cloud PBX
A cloud PBX is one part of a working phone setup. You need three pieces around it:
| Piece | What it does | Where it comes from |
|---|---|---|
| Internet connection | Carries your calls between your devices and the PBX | Your existing office or home internet |
| SIP trunk and numbers | Connects the PBX to the public phone network, so you can call and be called | A SIP trunk provider — see what is a SIP trunk? |
| Devices | What people actually talk into | Apps on computers and mobiles, IP desk phones, or both |
Some providers bundle all three. Others — including us — focus on the PBX and let you choose your own SIP trunk provider, which keeps you free to pick the best rates and numbers for your country.
Who a cloud PBX suits
A cloud PBX is a good fit when:
- you don't have, or don't want, someone in-house to look after phone hardware;
- your team works from more than one place — offices, homes, on the road;
- your headcount changes, and you'd rather adjust a number than buy more hardware;
- your old system is approaching the end of its life, or its lines are being switched off.
It's a weaker fit when your internet connection is unreliable and can't be improved, or when you have strict rules that every piece of equipment must sit in your own building. For a fuller comparison, read cloud PBX vs on-premise PBX.
How a cloud PBX is priced
Most cloud PBXs are priced per user per month — often with a discount for paying yearly. On top of that come the pieces outside the PBX: call charges and numbers from your SIP trunk provider, and any desk phones or headsets you buy. When you compare offers, check what's included: setup fees, minimum terms, features locked behind a higher plan, and what support actually covers. We walk through all of it in cloud phone system cost per user.
On PBXfactory
PBXfactory sells hosted cloud phone systems — today Yeastar P-Series Cloud on its Enterprise plan. You order it online in the portal, it's set up automatically (usually in under a minute), and the activation email makes you the PBX's admin. A seat — one user with their own extension — costs €4.99 per month or €54.99 per year, minimum 2 seats, prices excluding VAT. The number of seats also sets how many calls can run at the same time.
Your company's first PBX starts with a 3-day free trial for up to 10 seats. We run the PBX on our cloud, apply Yeastar's updates and keep an eye on it; you connect a SIP trunk from a provider of your choice. The full details are on our pricing page.