For decades, a business phone system meant a box in a comms cupboard: a PBX (private branch exchange) wired to desk phones and to the phone company’s lines. If you wanted to add a user, move office or let staff take calls at home, someone had to change the hardware.
A cloud PBX moves that system into a managed online service. Your numbers, extensions, call menus and voicemail live in the cloud, and staff make and receive business calls from approved desk phones, laptops, desktops or smartphones wherever they are working. This guide explains how it works, what you gain, and what needs to be planned so the switch goes smoothly.
How a cloud PBX works
Instead of travelling over traditional phone lines, calls are carried over your internet connection using VoIP (voice over internet protocol). The provider runs the phone system in its data centres; you manage it through an online portal.
- Desk phones plug into your office network and register with the cloud service.
- Softphones are apps on a laptop or desktop, used with a headset.
- Mobile apps let staff use the business number from their smartphone, so customers see the company number, not a personal one.
Because the system is not tied to one building, a user’s extension follows them. Someone working from home, in a branch office or on the road is reached the same way as someone at their desk.
What you gain
- Work from anywhere: office, hybrid and mobile staff on one system.
- Keep your numbers: existing business numbers can be ported to the new service.
- Smarter call routing: menus, queues, ring groups, opening hours and overflow routes send callers to the right team.
- Voicemail to email: messages reach people beyond their desk.
- Multi-site in one system: offices and remote users share one directory and one set of rules.
- Easy scaling: add or remove users without a PBX room or an engineer visit.
- Reporting and control: administrators can see call activity and change routing quickly.
- Integration: suitable platforms support click-to-call and connections to business systems, and many can work alongside Microsoft Teams.
Cloud PBX vs an on-premise PBX
| On-premise PBX | Cloud PBX | |
|---|---|---|
| Where it runs | Hardware in your building | Provider’s data centres |
| Remote working | Limited or complex | Built in |
| Adding users | Hardware and licences | A change in the portal |
| Maintenance | Your responsibility | Handled by the provider |
| Office outage | Phones go down with the building | Calls can be rerouted elsewhere |
| Cost profile | Up-front hardware | Monthly per-user subscription |
What to plan before you switch
The technology is only part of the project. Most problems with cloud telephony come from the planning around it, so these areas deserve attention before anything moves.
1. Number porting
In Ireland you have the right to keep your phone number when you move to a new provider, and ComReg’s rules govern how porting works. Porting still needs care: gather account details for every number, including fax and alarm lines, confirm which numbers move and when, and schedule the cut-over for a quiet period. Do not cancel old services until the port has completed.
2. Broadband readiness
Voice uses little bandwidth but is sensitive to congestion and jitter. Check upload capacity, prioritise voice traffic on your network where possible, and consider a backup connection. Our guide to leased lines, fibre and 5G covers the connection side.
3. Call flows
Design how calls should enter, move through and leave the organisation before configuring anything: opening hours, menus, who answers which queue, what happens when nobody answers, and where calls go out of hours or during an outage.
4. Emergency calls
Calls to 112 and 999 must work from every device, and emergency services need accurate location information. Confirm how your provider handles emergency calls for desk phones, softphones and home workers, and record each user’s address where required.
5. Analogue devices and the copper switch-off
Alarms, lift phones, door entry systems, franking machines and older card terminals often rely on analogue lines. eir’s copper network is being retired in phases, exchange by exchange, so list these devices now and plan a replacement or adapter for each.
6. Devices and training
Decide who needs a desk phone, who uses a softphone with a headset and who works mainly from the mobile app. A short training session on transferring calls, joining queues and checking voicemail avoids a frustrating first week.
7. Contracts
Check notice periods and early-termination terms on your current lines and phone system so you are not paying for two services longer than needed.
A typical migration, step by step
- Discover: review numbers, users, sites, call patterns, broadband and business requirements.
- Design: define routing, devices, schedules, queues, resilience and integrations.
- Port and deploy: configure the platform, prepare users and migrate numbers through a controlled plan.
- Support and improve: monitor the service, resolve issues and adjust call flows as the business changes.
Common mistakes to avoid
- Moving numbers before call flows are designed and tested.
- Forgetting a line that a device depends on, such as an alarm.
- Running voice over a congested connection with no prioritisation.
- No agreed plan for where calls go if the office goes offline.
- Treating the phone system as a separate island instead of part of the wider IT environment.
Frequently asked questions
Will call quality be as good as a traditional line?
On a suitable connection with voice traffic prioritised, yes. Most quality problems trace back to the network rather than the phone system.
What happens if our internet goes down?
Because the system lives in the cloud, calls can be rerouted automatically to mobiles, another office or a voicemail box. This is one of the biggest advantages over a box in the cupboard.
Can we keep our existing numbers?
Normally, yes. Existing business numbers are transferred through the porting process, planned to minimise disruption.
Do we need new handsets?
Not always. Some existing IP phones can be reused, and many users are happy with a softphone or mobile app. A short review of your current devices answers this.
Plan your move to a cloud phone system
Everything IT designs and supports VoIP and cloud PBX phone systems around your users, sites and customer call flows. We look at connectivity, user devices, Microsoft 365 and support arrangements together, so voice, connectivity and IT issues follow one support route.