What is a VoIP phone number?

In this guide, we explain everything you need to know about VoIP and more. Here already knowing you need a VoIP service? Click the button below and request a free quote.

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VoIP phone numbers are fast becoming one of the hottest technology trends on the market today, with consumers and businesses adopting them en masse. But what is a VoIP phone number? How can you get one in the UK? And notably, how much does it cost?

What is a VoIP phone number?

VoIP, or voice over internet protocol to give it its full name, is a telephone service delivered over the internet, rather than traditional PSTN or ISDN business phone lines

As is the case with many parts of our lives, the internet has redefined what's possible from a telecommunications perspective. It is VoIP that is at the forefront of that revolution. Larger businesses have been using this technology for quite some time. Still, it's only been in the relatively recent past that it's become more accessible to smaller businesses and even consumers. 

VoIP phone numbers

The most prominent distinction between old telephone services and VoIP numbers is that VoIP phone numbers aren't tied to a physical telephone line. While on the face of it, that may sound relatively unimpressive, it's a profound change and opens up a considerable number of opportunities. Gone are the days of needing to have multiple telephone lines for various numbers; you can now have single VoIP phone service and pretty much have as many numbers as you wish. As we'll explain further into this guide, you can get a number in any town, city or even country you choose. 

One word that stands out when it comes to VoIP numbers vs traditional fixed-line services - portability. Whereas you were previously tied to a single physical location with a VoIP number, you can take it anywhere with an internet connection. You could be on a far-flung beach and picking up calls on your UK phone number over the internet. The flexibility and portability a VoIP number gives you is simply brilliant.

What's driving the change to VoIP numbers in the UK?

BT Openreach is planning to turn off the UK's PSTN and ISDN networks in 2025. What does that mean in layman terms? Everyone will need to move to VoIP phone services. Whether you're a consumer or business, if you want to have a phone service other than your mobile, you'll need to upgrade to VoIP. While this may sound like a tremendous amount of upheaval and disruption, it's going to be hugely beneficial to everyone. You'll get more functionality, more flexible service, and you won't need one or more phone lines for it. Next, we'll look at all of the benefits moving to a VoIP number brings, hopefully encouraging you to take the plunge sooner rather than later.

Joining T2K is one of the best if not the best business decisions we've made.
Paul Crisell - Vale Veterinary Clinic
on Google

VoIP phone number benefits

As we've already mentioned, the most prominent benefit of a VoIP phone number is portability, but there's much more to them than that. Let's now look at the most significant benefits of using VoIP services over a traditional telephone.

  • VoIP calls are cheap - businesses have benefited from this for a while now, but calls made over the internet using VoIP are far more affordable than over traditional telephone networks. If you make many calls, you'll most certainly see a reduction in your bills, and if you make a lot of international calls, it'll be even more significant.
  • Get multiple VoIP numbers - with VoIP; you aren't limited to a single PSTN number or a handful if you're using ISDN. You can get pretty much an unlimited amount which can be hugely valuable for businesses that work in various parts of the UK and the world. Essentially you can get local VoIP numbers to support your business operations. So if you're running a marketing campaign in Newcastle, why not get a local number for it? 
  • Access many features - Consumers and smaller businesses have become accustomed to a limited feature set provided by their phones and phone services, but that's about to change. With service from a business VoIP provider, you'll suddenly get access to a range of features that were previously reserved for only large businesses. Think call recording, voicemail to email, auto-attendants and more. 
  • Continual service improvement - unlike your existing phone service, which is likely very rarely upgraded, a VoIP number and its service are regularly subject to improvements. As you are effectively sharing a cloud-hosted service with thousands of other people, it's in the provider's interest to invest in advance of their platform. It will be easy to switch between providers, that we will see fierce competition for your custom, with quality of service and features on offer at the heart of the battle.
  • Better voice quality - VoIP calls have come a long way in a short time in terms of quality, which is primarily down to the improvement of internet speeds and reliability than anything else. Today, you can use your VoIP phone number to make a call and enjoy crystal clear call quality with no dropouts or interruptions.
  • Option to use softphones - short for "software phone", a softphone allows you to take your VoIP number with you wherever you are. The best VoIP services will provide you with softphones that can be installed on your computer, laptop, tablet and even your mobile phone. These softphones connect back to your VoIP phone system across the internet regardless of your location. So you can take your home or business phone number anywhere.
  • Number portability - once you move your number to VoIP, it instantly becomes more portable. A VoIP number, by its nature, isn't tied to a physical piece of copper, therefore if you want to move your number to another provider, you can, and it's straightforward.
  • Say goodbye to your landline - many of us only have a landline to get internet service. It's not directly a benefit of a VoIP phone number, but come 2025, when BT switches off their PSTN network, you will no longer need to pay for a phone service that you never use (Hurrah). 
VoIP phone numbers
VoIP phone numbers yield a huge number of benefits and additional features

How does a VoIP phone number work?

VoIP providers such as ourselves have invested heavily into cloud-based phone systems, meaning those located in data centres across the UK. When you sign up for a service like ours, we'll provision you with a free UK VoIP phone number and arrange for your existing number to be "ported" across to us.

In years gone by, individual businesses would invest in telephone systems to give them more functionality, but those days are gone with a hosted VoIP phone number. You pay a monthly fee and get access to a state of the art phone system, one that arguably you wouldn't be able to afford if you were buying the equipment outright. Instead, you subscribe to the service and benefit from all of the great things a VoIP service has to offer. 

In another recent article, we answer the question "What is VoIP?" getting into the nitty-gritty from a technical perspective of how it works. If you'd like to learn more and see some diagrams of how calls are connected, click the link.

How does a VoIP phone number work
VoIP works by converting your voice into digital bytes before transferring them over the internet

How much does a VoIP phone number cost?

Remember that there are a couple of parts to your VoIP phone services. Firstly you have the service itself, which is usually charged on a per user basis. Typically a VoIP service like Horizon, our hosted system, will include a free local telephone number and even a certain amount of free calls per month. What isn't typically included in the cost is premium numbers that you may wish to add. 

Cost of VoIP numbers in the UK

In this section, we look at the current cost for various VoIP numbers, all priced on a per number per month basis. Please use these numbers as a guide; the pricing is accurate as of January 2022, but as you can appreciate, subject to change.

01 & 02 Geographic or local VoIP numbers (£3 per month)

These numbers are the least expensive, and as we mentioned, we often bundle a certain amount of them into service, effectively giving you free VoIP numbers.

03 Numbers (£3 per month)

03 numbers replace 0870 as non-geographic (i.e. national) numbers. They cost the caller the same to call as geographic (local) numbers, and importantly, they cost the same to call from a mobile or a landline and will be covered by most people's monthly free minute's allowance.

There are currently two types of 03 number:

  • 030 - used for not for profit organisations such as doctors, charities and schools.
  • 033 - all other purposes.

We recommend that these numbers are an excellent alternative to 08xx numbers, except for 0800.

0800 Freephone Numbers (£5 per month)

0800 freephone numbers are perfect for sales and marketing lines where attracting inbound calls is the strategy. Most people know that 0800 numbers are free to call - so they can be an excellent marketing tool.

As the caller doesn't pay for the call, you, the company, is charged instead how much will depend on your service agreement.

0845 Numbers (£3 per month)

0845 numbers were designed as Lo-Call numbers, meaning that they were charged at local rates (if called from a landline) regardless of what the caller was in the UK.

A significant disadvantage of 0845 numbers is that they are typically not included within mobile phone user's free monthly allowance, meaning that they would need to pay extra to call you. This puts people off and doesn't give customers the best experience, so we typically recommend you opt for 030/033 numbers instead.

056 New Voice Service Numbers (£3 per month)

056 numbers are new non-geographical numbers that have been created specifically for VoIP. So in the purest sense, they are UK VoIP numbers! The only disadvantage of these new numbers is that currently, some providers can't route calls to them. We're sure this will change in time, but it's something to be aware of.

0844/0843 (£3 per month)

0844 and 0843 phone numbers used to provide revenue sharing, i.e. the owner of the number and the company that uses it each gets a proportion of the income generated from the call. While on the face of it could be seen as a great way to make some extra money, charging your customers to call you isn't the fairest way to do business, especially as most of our calls these days are free. 

Of course, these numbers make good business sense for some companies, so we can provide them but don't usually recommend them.

0870 numbers (£3 per month)

Similarly to 0844 and 0843 numbers, 0870 numbers were initially introduced to allow companies to charge their customers for calls. Examples included helplines etc. Unfortunately, the numbers were regularly used abusively, and Ofcom eventually reduced their call costs to national rates. From a consumer perspective, good news, from a company standpoint, removes a potential way to generate revenue.

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

Features of a VoIP phone number service

We're not going to get into too much detail about the specific features that a business VoIP system can give you as we've covered it in other guides, but we will summarise, so you can see the added value switching brings.

Call handling

By using a VoIP phone service, you open up new possibilities in call handling. If you work in a small business, get ready to enjoy enterprise-grade features for low monthly costs. Hunt groups, presence, call forwarding, call screening and more.

Auto-attendant and music on hold

An auto-attendant is the automated way to route your customers to the correct person in your company. Gone are the days of needing a dedicated receptionist; with an auto-attendant, people are connected to the right person every time, minimising costs and improving customer experience. Want to go further than that? Add music on hold and even record your sales and marketing messages to play to customers while they wait.  

Call recording and monitoring.

Regardless of the industry, you're in, having the ability to record conversations that your team have with clients and suppliers can be crucial to handling complaints and disagreements further down the line. Once only used by companies in financial services, companies of all types are now adopting call recording to improve customer service and ensure accountability from both the customer's and the employee's perspective. One of the significant benefits of a hosted VoIP phone number is that you can both record and monitor calls regardless of your employee's location; it's great for training and ensures that your team always communicates to the best of their abilities. 


Today, most businesses will use a CRM, and by moving to VoIP, you pave the way for your phone calls to be integrated with your desktop applications. Think contact popping when someone calls, or even automatic call logging. It's powerful stuff.

Time of day routing, mobile apps and more 

There are too many features to get into right now; some of them may well be surplus to your requirements, with others being game-changing. The critical point to bear in mind is that our service will be continually developed, with more features being added over time. 

Ready to get your UK VoIP number?

2025 may seem like a long way away, but as we have hopefully demonstrated, you could be saving money and enjoying improved functionality now! We'd love to speak with you about your business and offer a free no-obligation quote so you can see for yourself how much you could save. All of our customers have a Dorset based account manager; you'll have their contact details, so you'll always be able to speak to someone you know. Join the thousands that trust T2k to provide their VoIP services.

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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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