The Best Business Phone Lines in the UK

Choosing the best business phone line is a must if you want to bridge the gap between your team, business partners, and clients. However, with the phasing out of PSTN and ISDN networks by 2027, British businesses must soon switch to a Voice over Internet Protocol (VoIP) provider to continue using a business phone line.

The deadline to change your landline provider may be fast approaching, but don’t worry – we’re here to help. We found RingCentral Premium is the best phone line for most businesses, closely followed by 8×8’s X4 plan for those after unlimited calling minutes. There are other options too, depending on your business needs and budget.

Below, we go through our top-rated VoIP phone line plans, detailing what businesses they are best suited to and why. We’ll also clarify how VoIP business phone lines compare to the traditional landline networks, and explain what the future holds for them further down.

The Best Business Phone Lines for UK Businesses in 2024

The best business phone lines help project and maintain a professional image of your business to customers. However, to keep their communication lines running, UK-based businesses need to transfer their business phone line to a VoIP phone line before the ‘Big Switch Off’ of UK landlines in January 2027.

VoIPs are highly reliable compared to sometimes spotty cellular mobile reception and offer significantly more useful features for your business, such as call queuing, forwarding, and voice/video conferencing.

Click here to jump to our guide to the differences between VoIP and traditional landlines, or read on below for mini-reviews on our favourite VoIP providers.

1. RingCentral Premium: Best Overall Business Phone Line Supplier Plan

Our extensive research concludes that RingCentral Premium is the best business phone line package you’ll find on the UK market today. Before we detail what we like and think could be improved about its VoIP service, here’s a quick run-down of the things you need to know about RingCentral Premium.

What do we like about RingCentral Premium?

Its Premium plan earned perfect marks in five of our eight testing areas, including its offering of the most extensive collection of call management tools from customisable greetings and call blocking to external video calling and call re-routing.

You can direct callers to the appropriate department via a virtual receptionist and manage call traffic using ring groups and call queues. Unlike 8×8’s X4 plan, it provides live chat functionality to talk to your customers, too, and we only found it was missing the automatic nuisance call screening offered by Dialpad Enterprise.

RingCentral Premium also seamlessly integrates with Salesforce and over 107 other CRM, helpdesk, workspace, email, and conferencing software. Uniquely, compared to the other providers we tested, it also integrates with customer live chat channels like WhatsApp (although there’s no SMS support), and it’s the only one to support initiating video calls via Microsoft Teams.

Crucially for businesses with high employee turnover, it also scored superbly for its range of training features, alongside 8×8 X4 and Vonage Max. We found it could do it all from recording calls and creating transcripts to live call monitoring, whispering, and call barging functionality.

Where Could RingCentral Premium Be Improved?

If you work on a marketing team, you may be less impressed by RingCentral Premium. Unfortunately, it doesn’t offer many outbound communications features, like power dialling or predictive dialling, making RingCentral unsuitable for outreach. You would have to buy the Ring Central Engage add-on to gain access to these outbound communication features.

At £24.99 per user, per month (when billed annually), it is also quite expensive considering it has capped inbound and outbound minutes per user of 1,000 and 2,000 respectively. Still, its set price point – as opposed to the unclear, bespoke costing model used by the likes of 8×8 and Vonage Max – is a benefit, however, and this number of minutes may still be enough for many teams.

If you need unlimited minutes, see the details on 8×8’s X4 package below.

What Businesses is RingCentral Premium Suited To?

Overall, RingCentral Premium is well suited to large-scale communications and improving customer service at medium-sized enterprises, such as healthcare (where it also took the top prize). Its array of communication channels and call management tools allow it to handle large numbers of calls at once without bother.

2. 8×8 X4: Best Business Phone Supplier Plan With Unlimited Minutes

While RingCentral Premium is a star performer, 8×8’s X4 plan was equal to or a jot behind it in many categories – and in one particular way, we think it’s an even better choice: unlimited calling minutes. Here’s a summary of everything, good and not so good, about 8×8 X4.

What Do We Like About 8×8 X4?

The 8×8 X4 plan performed exceptionally well on most bases, earning a score of 4/5 or higher in seven of our eight test areas. It performed particularly well due to its comprehensive training features, such as advanced tools like call barge and whisper, that match RingCentral Premium in terms of extent and variety.

Its help and support options are also to be commended, with 8×8 supplying 24/7 live chat support, an email and phone customer team plus an online knowledge base and user forum to help you through any problems you might encounter.

Where Could 8×8 X4 Be Improved?

The main area where 8×8 X4 performed below par was for its bespoke pricing. You’ll have to contact 8×8’s sales team directly for a quote, which we found a little unclear for potential customers.

And from what we do know about its X4 plan pricing, affordability is not 8×8’s strong suit: it’ll set you back around £36 per month when paying annually, according to our estimates. And this all saw 8×8 X4 get one of the worst scores in terms of affordability. Still, if you can match its monthly price, you’ll have a lot more features to play with than many other business phone providers.

The only other area where RingCentral Premium had it beaten was around software integrations. 8×8 X4 doesn’t support live chat integration, meaning businesses which regularly use this functionality should look elsewhere.

What Businesses Is 8×8 X4 Suited To?

Given it supports unlimited calling to 48 countries and has excellent support for internal communication via multiple channels, any businesses with global and international operations will find 8×8 X4 a solid candidate.

Its robust training features allow it to train staff effectively from remote locations, perfect for fast-growing teams, too.

3. Vonage Max: Best Business Phone Plan for Small Businesses

Vonage Max is our best phone line provider for small businesses since it provides excellent third-party integrations at a reasonable price. Here’s what you need to know about Vonage Max before we jump into the nitty gritty.

What Do We Like About Vonage Max?

Helping to improve the skill set of your staff, we found Vonage Max’s training features matched our two leading business phone providers RingCentral and 8×8. You’ll get call recording, monitoring, barging, and whisper functionality, plus analytics and reporting tools, all included to ensure new hire and existing staff productivity and proficiency keep at pace with your business needs.

In tandem with this were some well-equipped call management tools. Staff can feel empowered to perform all the actions they need to with handy outbound communication features, whether that’s screening live calls via caller ID or after missed ones via voicemails, re-routing audio or video calls, or setting up custom call lists to reach out to select customers quicker.

And when considering the bottom line, Vonage Max is a strong contender, too. At £25 per user, per month, it provides enough advanced features to warrant that price, including plenty of CRM integrations and unlimited inbound/outbound minutes which some providers struggle to match. Overall, only bOnline beat it in for value; bOnline is cheaper than Vonage, but also less robust, in our view.

Where Could Vonage Max Be Improved?

While Vonage Max integrates with major CRM systems and productivity tools like Salesforce and Hubspot, its potential amount and variety of software integrations do not match its rivals. Namely, we couldn’t fully integrate Vonage’s most expensive plan with any video conferencing or customer-service live chat apps. This could limit its utility for businesses with more extensive or complex software needs, even if calendar apps like Office 365 and Google Workspace are supported.

We weren’t overly impressed by Vonage Max’s communication tools either. While there’s support for messaging and video conferencing, which may be enough for some businesses, a lack of SMS or e-fax functionality could be a missing ingredient for others.

What Businesses is Vonage Max Suited To?

The no-contract and month-to-month payment schedules that Vonage Max offers are ideal for first-time VoIP businesses looking to try the technology out without any extensive commitments.

We also believe Vonage is a superb choice for small businesses that need an automated help desk for handling customer queries, such as solicitors, given its extensive call management features.

Otherwise, any small business with high call volumes should enjoy its unlimited inbound and outbound minute allocation.

4. GoToConnect: Best Business Phone Provider Plan for Hardware Integration

Our research shows that GotoConnect is another top business phone line provider. But one group of businesses should be interested in particular: those that already have existing phone hardware.

GoToConnect integrated with more desk phone brands than any other provider we tested. Here’s a brief look at why else the US-based provider could be for you.

What Do We Like About GoToConnect?

We awarded GoToConnect a perfect score for both its hardware integrations and communication channels.

On the hardware front, GoToConnect supported a broader range of phone manufacturers than any other VoIP business phone we tested. That should allow companies some greater flexibility to fit GoToConnect into their existing hardware or purchase the exact phone brand it requires without any restrictions.

Uniquely amongst the business phones we tested, GoToConnect could integrate with all the communication channels we required. That’s team messaging, e-faxing, plus audio and video conferencing for up to 250 participants in one seamless system. It even goes above and beyond as one of the few providers to support outbound SMS campaigns and is aided by AI-assisted personalisation and a multi-channel shared inbox to keep track of messages.

Where Could GoToConnect Be Improved?

GotoConnect has a limited number of CRM integrations and fewer training features than its competitors. It supports Salesforce and offers some API integrations, but lacks compatibility with other CRMs and software applications like Microsoft Teams. Similarly, while it provides basic call monitoring and recording, there are no call barge or whisper tools to help improve employee performance.

These absentees mean GoTo may not appeal to organisations looking to scale customer-service operations at pace, nor those with more complex workflows that could benefit from a VoIP that integrates with various software. 8×8, RingCentral or Vonage Max will be better options in this regard. 

GoTo also has fewer security measures in place compared to other business phone lines, lacking multi-factor authentication and extensive user permissions, which may pose riskier for businesses handling sensitive data.

What Businesses is GoToConnect Suited To?

It should be clear that GoToConnect is a solid choice for businesses that already own an extensive amount of desk phones due to its high compatibility with various phone brands (although, do always check your brand is compatible before purchasing).

Otherwise, organisations that want to improve their internal communications will thrive on the advanced features – from call routing and ring groups that help staff reach the right person in different offices to team chat and video conferencing options – GoToConnect offers that no other provider we tested could beat in our testing.

Adding these two ideas together, we believe businesses spread across different geographical areas should consider GoToConnect. Varied tools for internal comms and solid integration with various hardware types make it a superb candidate for teams that work remotely.

5. bOnline Unlimited Calling: Best Budget Business Phone Provider Plan

For a budget-priced business phone line that does the basics extremely well, bOnline Unlimited Calling is unquestionably our favourite option. Take a look at its scorecard below to get an idea of what its strong suits are.

What Do We Like About bOnline Unlimited Calling?

Prioritising affordability, whilst still offering core call management and communication functionalities like call routing, ring groups, and integrations with popular CRM and helpdesk applications, bOnline is an excellent value proposition first and foremost.

It includes unlimited calling minutes, as its package name suggests, although you now need to pay £5/month extra for call recording, HD video conferencing and CRM integration respectively. Depending on what your business requires, that can still work out much cheaper than other business phones on this page, you just won’t have as extensive options as RingCentral or 8×8 for training features or software integrations, in particular.

Where Could bOnline Unlimited Calling Be Improved?

While bOnline keeps costs low, it’s only seamlessly compatible with Yealink brand phones. Its most expensive Unlimited Calling plan does come with a handset for each user, however, this essentially locks your business into Yealink rather than a third-party option which may suit your business needs better.

bOnline also scores poorly for its less robust security measures. Even if it does have data security compliance certifications and password rules for users, businesses after complete peace of mind could find its lack of user permissions controls and multi-factor authentication a concern.

As alluded to above, it doesn’t have as extensive options for training – lacking call barge and whisper tools – or software integrations – not supporting third-party video conferencing, customer service live chat or calendar apps.

What Businesses Is bOnline Unlimited Calling Suited To?

The comparatively small monthly price point of bOnline’s Unlimited Calling plan makes it the number one choice for any businesses looking to minimise their costs without losing out on essential VoIP features.

As a result, first-time VoIP businesses should be attracted to its straightforward and streamlined offering. Similarly, small customer-service teams that require core call management features like call routing and software/CRM integrations – but don’t need all the tricks in the box for training staff provided by the likes of RingCentral and 8×8 – should look into purchasing bOnline.

The Types of Business Phone Line: PSTN, ISDN and VoIP

There are three types of business phone lines today: public switched telephone network (PSTN), integrated services digital network (ISDN), and voice over internet protocol (VoIP).

Public Switched Telephone Network (PSTN)

The Public Switched Telephone Network (PSTN) was the original technology for telephone communication invented in the late 1800s. It’s what we call a landline today—the copper telephone lines that run throughout your locale to transmit analogue voice.

Although we’re using modernised PSTN landlines compared to that era, the principle behind its technology has been essentially the same since its conception. And consequently, it’s outdated and expensive to maintain, with the PSTN network set to be switched off by 31 January 2027. Find out why this is important for your business here.

Integrated Services Digital Network (ISDN)

PSTN’s successor, the integrated services digital network (ISDN) launched in the late 1980s. It digitised the standard landline, enabling the simultaneous transmission of voice and data over copper PSTN wires.

Compared to its predecessor, it offers businesses clearer, higher voice quality with less distortion and faster data transmission. However, it still relies on the PSTN network for its use, essentially relaying data via more efficient digital transmission. And that means once PSTN switches off in 2027, ISDN will be switched off too.

Voice over Internet Protocol (VoIP)

Finally, we have Voice over Internet Protocol (VoIP), overtaking PSTN and ISDN connections in the business world. As the name suggests, VoIP refers to voice transmission over the internet instead of traditional, physical phone line infrastructure.

This eliminates physical communication barriers, creating a phone system that can grow as your business scales. With everything on a single data network instead of separate phone lines, features like call forwarding are made easier too, while introducing new ones such as video conference calls or voicemail to email data transfer.

It can even be integrated with other business applications such as e-commerce platforms and customer relationship management (CRM) systems. Overall, it outperforms all other business phone lines, particularly in terms of efficiency.

Landline Phone Lines vs VoIP Phone Lines

Now that we’ve defined the different types of phone lines, let’s go a little more in-depth into the difference between landlines and VoIP lines, focusing on three key categories: price, functionality, and mobility.

How Do We Compare the Best Business Phone Lines?

Expert Market researchers thoroughly evaluated the best business phone lines to help you find the perfect telephone system for your business, using the following key criteria to assess each provider.

Scoring Criteria with Respective Weighting

• Call Management (25%): an analysis of a given platform’s call management features, including call routing functionality and the presence of a virtual receptionist.
• Communication Channels (20%): assessment of the tools available within a VoIP platform for internal communication, including team messaging, video conferencing, and SMS capabilities.
• Training Features (20%): the ability of the VoIP service to support the training of employees, from call review features like call recording and call data reporting, to live call coaching features like call barge or call whisper tools.
• Pricing (10%): the pricing structure associated with the VoIP service, such as monthly subscription fees, call rates, setup fees, and any additional charges for add-on features or services.
• Software Integrations (10%): the VoIP service’s ability to connect and integrate with external software systems, such as integration varying CRM, helpdesk, and external video conferencing platforms.
• Hardware Integrations (5%): the ability of a VoIP service to integrate with different phone brands.
• Customer Support (5%): the extent of assistance and resources provided by the VoIP service provider to customers including technical support, online resources, and access to customer support representatives.
• Security Options (5%): the measures and features implemented by the VoIP service to ensure the confidentiality, integrity, and protection of voice communications and data.

Once our researchers collate all information and score each key category, we compute each business phone plan’s final scores and rank them accordingly.