For most UK small and mid-sized firms, the shortlist comes down to four routes. Voipfone suits low-use teams that want published allowances, Vonage Business Cloud suits mobile-heavy staff, Microsoft Teams Phone suits Microsoft 365 shops, and Gamma suits firms that want to keep an existing phone system on SIP trunks. Advertised prices run from £5 to £25 per user per month before VAT, so compare the full monthly bill, not the headline seat price.
What does a hosted business phone system cost in the UK today?
Published tariffs sit in a narrow band, but they buy different things. Voipfone's plan comparison lists £2 for Flex, then £5, £10, £15 and £20 per user per month, excluding VAT, for 100, 500, 1,000 and unlimited UK minutes. Each of those four tiers includes one UK 01, 02 or 03 number per account, and the page states no contract on every plan.
Vonage's UK pricing page lists Express at £10, Core at £15 and Max at £25 per user per month, and says all prices exclude VAT. Microsoft lists Teams Phone Standard at £7.70, Teams Phone with a calling plan at £9.20, with UK domestic calling at £13.10, and with domestic and international calling at £26.10. Those Microsoft prices are per user per month, paid yearly, on Microsoft's Teams Phone page, and a separate Teams licence is still needed.
Advertised price per user per month
List prices for selected plans from each provider's own UK page, checked on 1 November 2026. VAT treatment varies by provider.
View the data
| Category | £ per user per month |
|---|---|
| Voipfone 100 minutes | £5.00 |
| Voipfone Unlimited | £20.00 |
| Vonage Express | £10.00 |
| Vonage Core | £15.00 |
| Vonage Max | £25.00 |
| Teams Phone Standard | £7.70 |
| Teams Phone with UK calling | £13.10 |
| VoIP Shop Standard Voice | £13.95 |
| RingCentral Essentials annual | £12.99 |
These prices were checked on 1 November 2026. They are advertised list prices, not quotes, and your own bill will depend on numbers, handsets, call groups and calling volumes.
What are the alternatives to BT One Phone for a UK business?
Firms replacing a mobile-integrated service such as BT One Phone have three routes. The first is a business app on staff phones, offered by Voipfone, The VoIP Shop, RingCentral and Gamma Horizon Collaborate. The second is a plan that ties telephony to the mobile service itself, which on the pages reviewed means Vonage Max with its eSIM and business mobile number. The third is Teams Phone Mobile, which Microsoft says combines mobile calling plans from participating operators with Teams Phone. Which fits depends on whether staff must dial from the native handset dialler.
How do I choose between Voipfone, Vonage and Teams Phone?
Start with how your staff actually call. Pull three months of call records and sort users into light, average and heavy callers. Voipfone's tiers let you size allowances per user, so a team of mostly inbound callers need not pay for unlimited minutes for everyone.
Vonage splits its plans by what you need rather than minutes. Express covers unlimited inbound calls with a business landline number and a desktop app. Core adds unlimited outbound calls, CRM integration and Microsoft Teams compatibility. Max adds a VBC Mobile Connect eSIM, a business mobile number and unlimited SMS from the mobile, which is the one to demonstrate if your staff live on their phones.
Teams Phone works best where staff already live in Teams. The Standard licence is the phone system only. Microsoft says you add PSTN service through Teams Calling Plans, Operator Connect or Direct Routing, so price the complete setup before comparing it with an all-in-one plan.
Which providers include hunt groups, ring groups and call queues?
Several do as standard. The VoIP Shop's plans page lists Standard Voice at £13.95, Premium AI at £16.95 and Ultimate AI plus CRM integration at £23.99 per user per month, with unlimited UK mobile and landline calls, hunt groups, a call queue system and a mobile app on all three. The page does not say whether those prices include VAT, so confirm that in writing. Voipfone lists call groups at £1 each and call queues at £2 as add-ons, so its low headline price grows as you add features.
RingCentral's UK pricing page lists Essentials from £12.99 per user per month on annual billing (£17.99 paid monthly), with 100 inclusive minutes per user. Higher plans add minutes and advanced call handling such as whisper and barge, and the page offers custom bundles through its sales team. Its page does not state a VAT basis either.
Which features should I insist on seeing demonstrated?
A feature list is not a call flow. Voipfone states that voicemail, business hours, call diverts, call pickup and a softphone app come with every plan, and it lists call groups at £1 each as an add-on. That is a sensible base for a simple opening-hours setup.
Ask each finalist to show you three things working live. First, a hunt or ring group that falls through to a final destination when nobody answers. Second, time-based routing that treats a bank holiday differently from a normal Monday. Third, voicemail landing in one place whether the call came in on a deskphone, an app or a mobile. Do not assume a shared inbox across an independent mobile contract. Ask for it to be shown.
For a single voicemail inbox covering all business calls, none of the pages reviewed promises one shared mailbox across deskphone, app and an independent mobile subscription. Ask each provider to leave a test message on every route and show you where it lands. For multi-office firms, specify the dial plan, which site reception answers, opening hours per site and overflow destinations, then test transfers between offices and remote staff before approving the full move.
Who offers mobile integration, support and training?
If your staff relied on a mobile-first service, separate two needs. An app gives a business number on any smartphone, and The VoIP Shop, Voipfone, RingCentral and Gamma Horizon Collaborate all describe mobile apps. Mobile service integration is different, and Vonage Max is the plan above that names an eSIM and business mobile number.
Support is harder to compare from price pages. The VoIP Shop's support page gives a UK phone number, an email address and a ticket form for office hours. Gamma says it is responsible for the hardware, software and upgrades of its Horizon hosted system. None of the pages reviewed promises weekend installation in Manchester or Essex, training sessions or named references, so ask each finalist for those in writing.
Which UK providers offer SIP trunks and enterprise SLAs?
If you own a phone system that still works well, you may not need to replace it, and an enterprise telephony buyer can keep it on SIP trunks. Hosted systems like Gamma Horizon, Teams Phone and RingCentral are the alternative. Gamma describes its SIP trunks as connecting your on-premise telephone system to its network over an internet connection, with 99.99% availability advertised. It also says calls can be rerouted from an affected branch to another site at no extra cost.
For enterprise buyers asking about an SLA, treat that percentage as marketing until you have the contract. Ask for the measurement period, exclusions, service credits and support hours. Your own broadband, power and phone system remain part of the chain, so a trunk alone does not make a site resilient.
What does UK regulation say about moving numbers and emergency calls?
Keep your numbers. Ofcom explains that customers can take landline or mobile numbers with them when they change provider, under General Conditions B3 and C7. Ask every supplier who owns the porting project and what happens to calls on the day.
Emergency calls matter too. Ofcom's guidance says General Condition A3 requires providers to take all necessary measures to ensure uninterrupted access to emergency organisations, including when a power cut hits a customer's premises. The government's landline guidance adds that digital landlines cannot carry power, so handsets and routers need a battery or generator, and that providers recommend a mobile phone as backup for most customers.
What does a low-disruption migration look like?
The same government guidance says most customers are expected to complete the move to digital landlines by January 2027, and that not all analogue services will be switched off by then. So audit each line rather than assuming one deadline. Alarms, telecare devices and fax machines may need replacement devices or adaptors.
A sound sequence has six steps. List every number, range and attached device. Agree call flows and the power fallback. Pilot with temporary numbers on real desk and mobile devices. Confirm porting details and cutover responsibilities in writing. Test inbound and outbound calls, caller ID, transfers, groups and voicemail on the day. Keep agreed contingency routing until every number and site has been checked.
If you want an engineer on site, such as a weekend install in Manchester or Essex, make that a line in the order. A hosted plan page does not promise premises work, so ask for the date, the attendance and the cost in writing.
Sources
- Voipfone, Business plans comparison, 2026
- Vonage, Business phone plans UK, 2026
- Microsoft, Teams Phone, 2026
- The VoIP Shop, Plans and pricing, 2026
- RingCentral UK, Plans and pricing, 2026
- Gamma, SIP trunks, 2026
- Ofcom, Number portability, 2026
- Ofcom, Protecting access to emergency organisations in a power cut, 2023
- GOV.UK, UK transition from analogue to digital landlines, 2026
