Best business phone systems for UK small businesses (2026)

Choosing a business phone system is no longer just about making calls. It affects your costs, how easily customers reach you, how your team works from home or on the road, and the first impression people get when they ring. It is also a decision you may have to make soon anyway, because the UK's copper phone network is being retired, with the switch-off due to complete by 31 January 2027.

This guide explains the main types of business phone system, the features worth paying for, how to choose between them and how to switch without missing a call.

Key takeaways

• For most small UK businesses the best choice is a hosted VoIP phone system running on reliable broadband.
• A good system rings on desk phones, laptops and mobiles, so staff can work from anywhere with one business number.
• Features that matter most: call menus, call groups, out-of-hours routing, voicemail to email, mobile app and call reporting.
• You can keep your existing number. The new provider arranges the transfer.
• Compare total monthly cost, contract length, support and who you speak to when something breaks, not just the headline price.
• Plan for internet and power cuts, and check how 999 calls work.

What a business phone system costs in the UK

Most hosted phone systems are priced per user per month. Here is what PurpleBox costs for common team sizes, with and without unlimited UK calls.

All prices are per month and exclude VAT. Unlimited calls cover UK landlines and mobiles, with fair use of 2,000 minutes per user per month.

For comparison, UK price guides put typical business VoIP at £7 to £13 per user for basic plans and £14 to £20 per user with unlimited calls. Setup, number porting and support from our London team are included in our price.

What else might you pay for?

• Handsets. Optional. Many teams use the mobile and desktop apps instead. If you want desk phones, we supply business handsets and headsets.
• Broadband. Your phones run over your internet connection. If yours is slow or unreliable, we will tell you before you switch.
• Calls outside the UK. International calls are charged separately.

Already paying less, or locked into a contract? Call us on 020 7613 1378 and we will compare it with your current bills.

Why does your phone system matter?

If you are still on a traditional landline, or juggling several mobile numbers, an upgrade pays off in three ways.

• Cost. Hosted systems typically charge per user with UK calls usually included, instead of line rental on every number plus call charges. The best way to see the saving is to compare a quote with your current bills.
• Flexibility. Whether you run a remote team, take calls on the road or work from a shared space, modern systems follow the person, not the desk.
• Scalability. Adding or removing a user takes minutes, and you do not have to change number or sign up to a long contract just to grow.

For the basics of how it all works, read our VoIP guide.

Which features should you look for?

Not every business needs every feature, but these are the ones small UK teams find most useful.

1. Call routing and an auto-attendant. Callers press 1 for sales or 2 for support and are sent to the right person or group. It makes even a very small business sound professional.
2. Voicemail to email. Missed a call while with a client? The message arrives in your inbox as audio or a transcript.
3. Mobile and desktop apps. Take your business line anywhere, and make calls showing your business number instead of your personal mobile.
4. Call reporting. See your busiest times and how quickly calls are answered, so you can staff properly and improve service.
5. CRM integration. If you use HubSpot, Salesforce or a similar tool, linking it to your phones saves time and logs conversations automatically.
6. Call recording. Useful for training and records, but it brings legal duties. See our guide to GDPR and call recording.
7. Team messaging and video. Often included, which can replace a separate meeting tool.

Types of business phone systems

1. Hosted VoIP (cloud phone system)

Your numbers and call handling live in the provider's data centre. You use desk phones, apps or both. There is nothing to maintain in your office.

Best for: most small and growing businesses, hybrid teams, businesses with more than one site.

2. Microsoft Teams Phone

If your team already works in Microsoft 365, Teams can make and receive normal phone calls with an add-on licence and a calling plan or an Operator Connect provider.

Best for: businesses that live in Teams all day. Watch out for: licensing complexity and fewer call-centre features than a dedicated phone system.

3. On-site PBX

A traditional private branch exchange with equipment in your office. Many are now hosted, which blends the old and new models.

Best for: businesses with specific integration needs and in-house IT. Watch out for: older ISDN-based systems stop working at the copper switch-off.

4. Mobile-based systems

Business calls routed through an app on your existing mobile plan.

Best for: sole traders and small field teams. Watch out for: no shared call queues, and personal and business calls can get mixed.

How many phone lines does a small business need?

With a hosted phone system you no longer buy "lines" in the old sense. You pay per user, and every user can make and take calls at the same time. A 2-person office and a 4-person office get the same features. The only difference is how many people are set up.

As a rough guide:

• 1 to 2 people (sole traders, partnerships): one business number that rings both mobiles and a laptop. Add a simple menu if you want to sound bigger.
• 3 to 5 people (small office): a main number that rings everyone, or a menu sending callers to sales, accounts or support. Voicemail to email for missed calls.
• 6 to 20 people: call groups for each team, out-of-hours routing and call reporting so you can see when calls are being missed.
• 20+ people or a reception desk: call queues with hold music, a receptionist view of who is free, and reporting on answer times.

On a traditional system, a "4-line phone system" meant four calls could happen at once. With hosted VoIP, every user can be on a call at the same time without buying extra lines.

Looking for a BT One Phone alternative?

BT One Phone combines mobile and office calls through BT's mobile network. If you are on it now, or are looking for a replacement, a hosted VoIP system can give you the same thing without being tied to one mobile network:

• Your business number rings on staff mobiles through an app, on any network.
• Staff can call out showing the business number, not their personal mobile.
• Desk phones are optional, so office and mobile staff use the same system.
• Call menus, groups, voicemail to email and reporting are included.
• You can keep your existing numbers. We handle the transfer.

If your team mostly works on mobiles, tell us when you call and we will set the system up mobile-first.

The best phone system for a mobile or hybrid team

For teams that are rarely at a desk, the best setup is usually a hosted system with a good mobile app rather than a mobile-only plan. You get:

• one business number, whoever answers
• calls that ring on the app and move to a desk phone or laptop when someone is in the office
• shared call groups, so a customer's call is not missed because one person is driving
• separate business and personal calls on the same handset

How to get an affordable business phone service

The cheapest headline price is not always the cheapest bill. To keep costs down:

1. Pay per user, not per line. Stop paying line rental on numbers nobody uses.
2. Get calls included if your team is on the phone a lot. Per-minute charges add up quickly.
3. Use apps before buying handsets. Many staff never need a desk phone.
4. Check the contract. Long contracts and exit fees can cost more than a slightly higher monthly price.
5. Cancel what you no longer need after switching: old lines, fax numbers and ISDN channels are often still being billed.

How do the options compare?

How do you choose the right system?

Ask yourself:

• Do I need to take calls from anywhere?
• Will the team grow soon?
• Do I need call menus, call groups or voicemail to email?
• Do I use a CRM or other software I want to connect?
• What happens to calls if my internet or power fails?

Tips by business type:

• Consultants and services: hosted VoIP with a mobile app, call scheduling and CRM integration.
• Remote and hybrid teams: hosted VoIP with team messaging and video.
• Retail and hospitality: simple hosted VoIP with an auto-attendant and voicemail to email.
• Offices with existing Microsoft 365: compare Teams Phone against a hosted system on cost and features.

When you compare suppliers, check:

• Pricing: clear monthly fees with no hidden extras, and what is included in calls.
• Contract: length, notice period and exit charges.
• Support: UK-based, easy to reach, and one named contact.
• Setup: who handles number porting, handsets and call flows, and how long it takes.
• Resilience: backup connection, mobile forwarding and 999 handling.

How do you switch without losing calls?

1. List every number and every device on a phone line, including alarms and card machines.
2. Check your current contract end dates and notice periods.
3. Check and, if needed, upgrade your broadband first. Our FTTP guide explains the options.
4. Build the new system in parallel, with users, menus and voicemail ready.
5. Port your numbers and test calls on the day.
6. Cancel the old lines once everything works.

Read our guide on alternatives to BT for more on the switch-off and what else stops working.

How PurpleBox can help

PurpleBox supplies and supports hosted business phone systems for UK businesses, with the handsets, broadband and security to match. We handle the audit, number porting, call flows and training, and we stay your single point of contact afterwards.

See business communications · Case study: a simpler phone system · Request a callback

Frequently asked questions