The Best Call Centre Phone Systems in the UK

This post gives you a round-up of the best call centre phone systems currently available in the UK and detail how hosted VoIP can benefit businesses with inbound and outbound teams.

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The best call centre phone systems

Based on our independent research, customer reviews, and industry awards, the five best phone systems for call centres currently are:

Best all round
Gamma Horizon
Gamma Horizon

Best for: businesses looking to scale in the future

Gamma Horizon is a market-leading hosted VoIP phone system that can support anything from 1 to 500 users. While out of the box, it's a powerful solution that fits almost any business; by adding on their Call Centre functionality, you unlock a powerful suite of tools designed specifically for call centres.

Top features and benefits:

  • Generous free call bundles
  • Excellent choice of handsets and headsets from Polycom and Cisco
  • Call recording and monitoring
  • Work from anywhere
  • CRM integration
  • Wallboards
  • Extensive call routing options
  • Amazing auto attendant (virtual receptionist)
  • Dedicated supervisor interface
  • Guaranteed service availability
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Most flexible

Best for: businesses wanting more flexibility from their phone system

3CX is a phone system that can be deployed almost anywhere. You can host it on your premises, in your private cloud or in 3CX's cloud environment. Given that you're getting your own instance of the phone system, not just a shared platform, there is enormous flexibility in how it can be configured. It's an excellent choice for those looking for a more bespoke solution.

Top features and benefits:

  • Choice over where it's hosted and your SIP provider
  • Supports all IP phones and headsets
  • CRM integration
  • Create voice apps to automate repetitive tasks
  • Call recording and monitoring
  • Call queuing and routing
  • It can be integrated with voice payment gateways
  • Work from anywhere
  • Live chat for your website
  • Connect your Facebook page and
  • Business text messaging
  • 3CX Wallboard
  • Excellent auto attendant (virtual receptionist)
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Ringcentral Ringcentral

Best for: businesses that are looking for unified communications

Ringcentral is a powerful cloud VoIP solution that's well placed to help corporate companies looking for a unified communications solution. While they offer features suited to small businesses as only bigger companies get dedicated support, we think it's a solution that's best for the big boys.

Top features and benefits:

  • AI digital routing interprets inbound calls
  • IVR to enable self-service
  • Workforce management tools
  • Excellent Supervisor tools
  • Call recording and silent call monitoring
  • Agent tools such as script assistance and call transfer
  • Skills-based call routing
  • Analytics for every interaction
  • Speech and text analytics
  • Feedback forms and agent scoring
  • Real-time dashboards
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8x8 8x8

Best for: large international businesses

8x8 are one of the leading providers of hosted VoIP and for a good reason. Their platform is hugely scalable and perfect for companies looking to expand overseas or those with offices around the globe. Their call centre solution, "Contact Center", is packed full of useful features to help agents and supervisors deliver high-quality service to their customers. While it's not the best solution for UK only businesses or small businesses for that matter, 8x8 is excellent for bigger international firms.

Top features and benefits:

  • Omnichannel call routing
  • Proactive self-serve options
  • Excellent IVR
  • Predictive dialler, great for outbound
  • Call & screen recording
  • Customer surveys built-in
  • Integrates with popular CRMs
  • Built-in payment processing
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Avaya Avaya

Best for: an intuitive user experience

The last provider to make our shortlist is another international business VoIP provider Avaya. What we've been really impressed by with Avaya is how intuitive the interface is; it's incredibly user-friendly. The downside is the cost, as it's one of the more expensive options in this list, but there are still plenty of reasons to choose an Avaya call centre phone system.

Top features and benefits:

  • An extensive list of integrations
  • Easy to manage
  • Userfriendly interface
  • Lots of call centre focused features
  • Multi-channel communications with higher plans
  • Real-time and historical reporting
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How to choose the best provider for your business

With many leading VoIP providers in the UK, finding the best for your call centre can be a bit of a challenge. It's why here at T2k, we offer a completely free comparison service. All you need to do is tell us a bit about your requirements, and we'll do the hard work for you, coming back to you with personalised recommendations for the VoIP solution best suited to your business. At T2k, we're entirely brand agnostic, we're an independent company, so you benefit from free, impartial advice on choosing the best phone system for your call centre. To request a free comparison quote, please click the button below, and we'll do the rest.

How can hosted VoIP benefit your call centre?

Hosted telephone systems typically use VoIP, the technical term for phone calls made over the internet. Business VoIP differs from services like Skype because the phone systems come with a vast amount of functionality, allowing you to maximise efficiency in your call centre. In another recent post, we've detailed the benefits of VoIP for business, but seeing as this post is about call centre phone systems, let's look at the specific benefits companies with inbound and outbound teams can leverage.

Man in a call centre using VoIP phone system to make outbound phone call
Cloud phone systems yield significant benefits to businesses with call centres

Reduce costs

VoIP, in general, significantly reduces costs for a call centre in several ways. Firstly, most of the leading providers include a large number of free calling minutes in their packages, so for most, outbound call costs are minimal, and even if you go above those free limits, call charges are usually much lower than they would be using a traditional phone line like ISDN. On that note, older ISDN lines (which are being phased out) are expensive, whereas, with a hosted VoIP phone system, everything is done over the internet, so as long as you have a good internet connection, you don't need the additional ISDN cost. One thing to bear in mind is usually it's wise to have a separate internet connection for your phones to avoid your web browsing affecting call quality, but still, it'll be a lot cheaper to do that in comparison to having an ISDN line.

With VoIP, as you're effectively dealing with data, you don't need handsets in your business. Many of our customers will have desktops or laptops and then have headsets for their agents that connect to those devices. This again significantly reduces costs and minimises the investment in hardware you need.

Finally, as we'll explain further in this section of our guide to the best call centre phone systems, all of the efficiency features that VoIP systems give you access to reduce indirect costs and minimises the number of people you need to handle calls.

In our experience here at T2k, companies switching to VoIP save 47% on their telecoms compared to older technologies.

Call centre worker working from home using VoIP phone system

Work from anywhere

Thankfully, things are starting to get back to normal in the UK following the pandemic. However, many companies and their employees want to retain some flexibility over where people work. We have customers that have decided to close their offices as they've found a home working to be just as productive, with others adopting a hybrid arrangement where employees spend some time at home and in the office. Whichever camp you fall into, and even if you want your team to be in the office most of the time, having the ability for your employees to work from anywhere if they need to is a huge benefit.

Simply put, your team will be able to make and receive calls from anywhere they have an internet connection. They could be at home with a laptop and a headset or even overseas using a mobile app, and they'll be able to pick up business calls.

Call monitoring, recording and reporting

A vital aspect for businesses that operate call centres, be that sales, customer services, or technical support, is understanding how teams and individuals perform. As now explained, a hosted call centre phone system will have many features designed to give supervisors and upper management the visibility they need to make decisions and improve service.


All of the best call centre phone systems will include software that allows you to have wallboards in your office, showing key information about how call centres perform. Examples include:

  • Call waiting times.
  • The number of missed calls.
  • Average call length.
  • The number of busy agents.
  • And more.

Wallboards are designed to give supervisors key information about the performance of the call centre and team members. They're a hugely helpful way to set and monitor KPIs, so everyone knows how the team is performing against targets management have set.

The VoIP phone system from T2k has saved us serious expenditure and has changed the way we work for the better.
Steve Knell - Altogether Care
on Google

Call monitoring

Whether you use it for training or other purposes, monitoring active calls is very valuable in a call centre setting. Supervisors can listen to calls in real-time as agents take them. And with an additional feature, often called "Call Barge-In", the supervisor can even join the conversation, which is excellent from an escalation perspective, or when an agent is struggling with the call.

Call recording

Pretty much all of the leading hosted VoIP phone systems for call centres will include call recording, which for some will be a necessity to comply with legislation. Even if you don't work in an industry where it's mandated to record calls, there are numerous benefits of doing so, not least to protect your team from abuse. Call recording also opens up training and dispute resolution options for call centres. Given that most VoIP solutions include it as standard, it's something we'd always recommend is configured.

Call reporting

Finally, a call centre phone system will come with extensive reporting functionality, allowing supervisors and management to see how teams and individuals perform against KPIs quickly. With access to a vast amount of historical and real-time data, management can identify issues, spot resource gaps in peak times and find opportunities for improvement.

Woman using VoIP phone system while working in a UK based call centre
VoIP phone systems improve efficiency in a call centre

Enhanced call management

VoIP call centre solutions, such as Gamma, 3CX and Ringcentral, come with extensive call management features designed to streamline processes and ultimately improve customer experiences. Calls can be quickly escalated, and supervisors can join calls when they need to. Not only that, but if your team receives inbound calls on behalf of numerous brands or companies, with features like call whisper, they'll receive a notification as the call comes in, so they know how to greet the caller.

Advanced call routing

How calls are routed before reaching your team has a considerable impact on customer experience and operational efficiency. With a hosted VoIP phone system, you'll get access to call routing features that have typically been reserved for larger companies in the past.

Hunt Groups

Firstly, the use of hunt groups ensures that everyone in a call centre team can take the inbound call if they are available. Far from just being multiple phones ringing simultaneously, your phone system can be configured to distribute calls in many ways, from sending calls to the individual that has been idle for the longest to connecting more calls with high-performing agents. Hunt groups even work across sites and while your agents are working from home, so wherever team members are, they'll be able to take calls.

Auto Attendant (IVR)

Another crucial part of call routing is using an Auto Attendant, which acts as a virtual receptionist for your call centre. As people call your business, they'll be presented with several options to choose from, and depending on their choice, they'll be routed to different destinations. It could be that you have a relatively simple setup with just a few options to choose between. Equally, you might use multiple menu levels to understand precisely what the person is calling about so you can put them through the best agent straight away.


A customer relationship management (CRM) system is often at the heart of interactions with customers in a call centre. One of the brilliant things with the latest cloud VoIP solutions is integrating with that software. Agents will quickly get the complete picture when speaking to callers, being able to surface purchase history, past interactions, ticket status and more. Integrating your phone system with your CRM will dramatically speed up calls, reducing costs and giving customers the best experience possible.

Man on the phone listening to music on hold from a voip phone system

Marketing On-hold

Invariably when people call your business, they may end up on hold or in a queue at some point. While most companies will want to minimise the number of times customers is waiting, there is an opportunity to play messages to them while they wait. You could, of course, just choose to play music, but what many UK businesses are now doing is playing pre-recorded marketing messages. It could be that you're about to launch a new product, or perhaps you just want to communicate essential customer information before they reach one of your agents. Either way, that time on hold isn't wasted; it's put to use in a valuable way.

Outbound calls

For many call centres, outbound calls are a crucial part of their strategy, especially when it comes to sales. With a VoIP system, your agents will have the ability to choose which number they would like to present to the person they are calling. This is great if you're running a campaign in a specific geographic area, or even if you're calling on behalf of another company, as you can choose which number to present to the recipient. 

Web management and administration

The final significant benefit to a cloud-hosted VoIP phone system for call centres is how easy they are to manage and administer. Supervisors, managers and IT teams can log in to a web portal at any time and make adjustments to how calls are being handled. It could be that several agents suddenly go home sick, and you want to send calls elsewhere quickly, or even perhaps play a recorded message alerting customers they may need to wait a little longer. With a hosted phone system, almost anyone in the organisation, assuming they have the appropriate permissions, can change the configuration to react to what's happening on the given day. Typically, IT managers love these systems because it reduces the amount of time they need to put into managing the phones.

Configuring your call centre phone system to get the most from it

As we've illustrated, VoIP phone systems for call centres are powerful and allow both small businesses and large to operate highly efficiently. However, to get the most from these brilliant platforms, it's essential that you work with a partner that understands not only the tech but the market that you work in. By working with an independent provider like T2k, regardless of the size of your business, you know that you'll be listened to and have a team of experts that is proactively suggesting ways your system could be configured to give you maximum benefits. One of the downsides of the huge providers, like Ringcentral, is that unless you're a blue-chip company, you're unlikely to get a very personal service and may well miss out on some of the benefits of VoIP.

As we mentioned earlier, here at T2k, we're an independent business telecoms provider, and we work with companies in a variety of sectors across the UK. We aren't tied to a single solution or provider, which means we can give you honest advice on the best system for your business and call centre. If you want to work with a company that puts its customers first, please get in touch, and we'll help you find the best phone system for your business.

Lee Clarke
Sales Director

Having worked for T2k for nearly 25 years, it's fair to say that Lee is an expert when it comes to all things telephony and business communications. Overseeing the commercial side of the business, he has helped the company evolve and grow through the decades. In recent years, and with the advent of VoIP and hosted telephony, Lee has made sure that T2k is at the forefront of technological developments. With a firm interest in helping businesses navigate the world of telecoms, Lee is responsible for the majority of the content on this website.

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