The 3CX Phone System provides software-based business telephony over the internet, enabling UK organisations to replace ageing PSTN and ISDN lines before the 2027 switch-off. Businesses manage calls, internal communications, and customer contacts without copper network dependency.
Unlike traditional PBX systems requiring on-site hardware installations, 3CX operates purely as server software. Companies host it in the cloud, on internal IT infrastructure, or via UK telecom partners. This delivers complete telephony control through modern VoIP capabilities without physical equipment.
The 3CX Phone System is a software PBX designed to manage all business calling through VoIP. It replaces traditional telephone exchanges with a digital platform that connects phone numbers, users, and devices over the internet.
3CX telephone system acts as the central point for:
With 3CX, businesses avoid buying or maintaining expensive PBX hardware because everything runs on software. You can easily add new users, departments, or phone numbers through the simple management interface with no need for extra equipment
Every 3CX setup centres on a main server that handles calls and applies your routing rules. When a customer rings your business number, your SIP provider sends the call over the internet to the 3CX server. The system then directs it exactly where you’ve configured it to go.
Employees handle calls seamlessly on desk phones, computers, or smartphones. Since every device links to the central 3CX system, staff switch locations while keeping their business identity and extension number.
For example, 3CX can:
Send calls to a receptionist during office hours
Route callers to a sales or support queue
Play recorded messages if staff are busy
Forward calls to mobile phones outside office hours
UK organisations increasingly rely on 3CX to shift from PSTN and ISDN lines. With the copper network phasing out, internet-based calling becomes essential for ongoing voice services.
By connecting 3CX to UK SIP trunk providers, businesses can:
Many companies also choose to host their 3CX server in a UK data centre to reduce call latency and meet local data handling expectations. Most UK deployments use 3CX-supported SIP trunk providers with UK geographic numbers and 999 emergency calling over VoIP.
One of the main reasons businesses choose the 3CX telephone system is its flexible hosting model. Unlike many cloud-only phone systems, 3CX allows organisations to decide where and how the system runs.
3CX can be deployed:
This flexibility allows companies to balance cost, control, and technical responsibility. Some businesses prefer full control of their own server, while others prefer a managed hosting service.
The 3CX VoIP platform uses internet connections to carry voice traffic instead of analogue or digital phone lines. This allows much more flexible call handling than traditional phone systems.
With a 3CX phone system, businesses can design call flows that match how their teams work. For example:
Sales calls can go to a queue with multiple agents
Support calls can be prioritised by department
After-hours calls can be redirected to voicemail or mobiles
Overflow calls can be sent to another office or team
Because all call routing is software-based, changes can be made quickly without rewiring or installing new phone lines.
The 3CX phone systems platform includes a wide range of tools that go beyond basic calling. These features are designed to help businesses manage customer contact and internal communication more effectively.
Core features include:
Digital receptionists and auto attendants
Call queues and ring groups
Voicemail to email
Integration with Microsoft 365 and CRM platforms
Desktop and mobile softphones
Video meetings and screen sharing
Website live chat and messaging
Call recording and reporting
All of these features are controlled from a web-based management portal, allowing administrators to configure how calls are handled and how users access the system.
UK organisations choose 3CX because it is designed to fit how modern British businesses operate as the PSTN and ISDN networks are switched off. It works fully with UK SIP trunks, geographic and non-geographic numbers, and 999 emergency calling, making it a safe replacement for traditional phone lines.
3CX also gives businesses full control over where their phone system runs. Companies can host it in the cloud, on their own servers, or with a UK telecom provider, allowing them to meet data, security, and performance requirements.
The licensing model is another major reason companies move to 3CX. Instead of paying per user, businesses pay only for the number of simultaneous calls they need, which keeps costs predictable and affordable as teams grow.
See why businesses pick 3CX over alternatives
3CX gives UK businesses more control and flexibility than traditional phone systems and many cloud platforms.
Keep the same business number and extension wherever staff work
Works with Microsoft 365 and CRM systems
Supports remote, hybrid, and multi-office teams
Make and receive calls on desk phones, computers, or mobile apps
Built-in video calling, chat, and screen sharing
web-based control panel for easy user and call management
The right 3CX setup depends on how your business operates. Small companies with limited IT resources often choose a hosted 3CX service where the provider manages the server, updates, and security. Larger or multi-site organisations may prefer to run their own server or use a dedicated UK hosting provider for greater control.
Call centres, professional services firms, and organisations with high call volumes may also require more advanced routing, reporting, and redundancy, which can influence how the system should be deployed. Comparing different 3CX setups helps businesses choose the option that best fits their size, call traffic, and support requirements.
UK businesses pick between cloud data centres, their own servers, or managed providers for 3CX hosting. Cloud keeps things fast and secure while managed services handle all the upkeep. Your choice sets the pace for performance and maintenance duties.
3CX needs a SIP provider for geographic numbers, business lines, and 999 emergency calls. This trunk links your system straight to the UK phone network so calls flow both ways. Shop around for the best rates and reliability.
With hosting and SIP sorted, install the server, enter your licence, and assign numbers. Calls start working right away outbound and inbound without a hitch. Basic setup wraps up quickly for most teams.
Give each employee their extension, voicemail, and apps for desktop or phone. Staff pick up calls from office desks, home setups, or mobiles using the same business number. Remote working kicks in from day one.
Set up auto attendants, queues, office hours, and after-hours paths so customers hit the right desk fast. Ring groups and time-based rules keep things smooth round the clock. Customers notice the difference immediately.
Run full tests on calls, ported numbers, and emergency services prior to killing PSTN lines. Check every scenario to catch glitches early. Go live only when reliability hits 100%.
3CX does not charge per user. Instead, pricing is based on how many calls can run at the same time (called concurrent calls). This means your team can grow without increasing your licence cost, which makes 3CX far cheaper than most cloud phone systems.
UK businesses usually pay for four things:
Small offices can run 3CX on low-cost licences, while call centres use higher call-capacity plans. The real cost depends on call volume, not how many employees you have.
See why businesses pick 3CX over alternatives
3CX is software, not a complete service, so most UK businesses work with a provider to host, connect, and support it. choosing the right Provider is critical to call quality, security, and reliability.
When comparing 3CX providers, look for:
A good provider ensures the system is matched to your actual call volumes and business structure, not sold as a one-size-fits-all package.
Compare UK 3CX providers
Most UK 3CX providers operate from local data centres and use certified SIP trunk partners. This ensures calls are routed through UK networks, emergency services work correctly, and data is handled in line with local standards.
Many providers also offer service level agreements, regular updates, and certified 3CX engineers, giving businesses confidence that their phone system will remain secure and reliable.
Multi-site SMEs that need one phone system across offices
Call centres that require queues, recording, and reporting
Professional services firms using CRM-integrated calling
Businesses moving away from PSTN and ISDN
3CX is powerful, but it is not completely hands-off.
These are normal trade-offs for a system that gives this level of control.
Traditional phone systems use fixed lines and on-site PBX hardware. They are costly to maintain and difficult to scale.
3CX replaces this with software-based VoIP, allowing businesses to:
Prepare for the PSTN switch-off
3CX offers more control than fully managed cloud phone systems but requires more setup. Businesses that want
often choose 3CX over platforms that bundle everything into one fixed subscription.
We are here to help UK businesses make the right phone system choice without guesswork. Instead of pushing one provider or package, we compare platforms like 3CX, their hosting options, pricing models, and UK providers side by side so you can see what actually fits your business.
Our goal is simple: give you clear, unbiased comparisons so you choose a system that works for your size, budget, and call needs — not one that looks good in a sales pitch.
Not sure which phone system fits your business?
Before moving to 3CX, UK businesses should check:
These decisions directly affect call quality and reliability.
Yes, 3CX runs as a VoIP phone system over the internet, skipping traditional phone lines completely. Calls convert to digital signals that slash costs and work perfectly for remote teams. Businesses use it to replace PSTN and ISDN ahead of the 2027 cut-off without hassle.
3CX saves money because it charges for simultaneous calls, not every team member. Your staff can grow without those steep per-user fees that hit other systems hard. Check different hosting deals to see the real difference.
You can set up 3CX on your own kit or go with a UK hosting partner lots choose managed service. They handle the updates, keep security solid, and make sure calls never drop. Pick whatever matches your tech setup.
Yes, 3CX takes over as your software PBX, managing all call routing without expensive on-site boxes. Teams control everything through a straightforward web dashboard. Setup stays simple and costs drop long-term.
Yes, you port across all geographic and non-geographic numbers through SIP trunks. Customers keep dialling the same lines after you switch over. Just compare providers on porting speed and costs upfront.
Look at hosting options, SIP line rates, how many calls run at once, and the support you’ll get. These bits decide your costs and reliability most. Line them up properly to avoid the wrong choice.
Yes, small UK firms choose 3CX for unlimited users under one licence that scales cheaply. Growth never spikes your bill, and features match bigger outfits. Professional calling comes without legacy hardware expense.
Yes, employees handle calls on desktop or mobile apps from any location with their same extension. They keep business numbers wherever they go, no extra lines needed. Hybrid setups run seamlessly every day.
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