Openreach retires the PSTN on 31 January 2027. Here is an honest UK comparison of the main business VoIP providers, with published GBP pricing and what each one actually suits.
Openreach switches off the PSTN on 31 January 2027. That's the analogue phone network most UK landlines still run over, and when it goes, anything plugged into it stops working. In February 2026 Openreach said around 2.8 million lines still need to migrate, with more than 500,000 of them serving business premises.
If one of those lines is yours, you have about six months to move, and the copper is getting more expensive every quarter while you decide.
This is a buying decision, so here's the short version before the detail.
Which VoIP provider suits which business
- You already run Microsoft 365. Microsoft Teams Phone is usually the cheapest sensible answer, from £7.70 per user per month ex VAT on an annual plan, because your users, directory and devices are already there.
- You want one supplier for calls, video and messaging with a price you can read on a website. RingCentral and Vonage both publish UK pricing.
- You handle high call volumes and need proper queueing and reporting. 8x8 is built for that, though you'll need to ask for a quote.
- You'd rather pay for the system than per head. 3CX charges per simultaneous call, per year, so a team where most people rarely pick up the phone can come out well ahead.
- You want a UK carrier and a named human to call when a number won't port. A UK wholesale platform such as Gamma Horizon, bought through a partner, is the usual route.
There's no single winner here. The right choice depends on how many of your people are actually on the phone, what you already pay Microsoft, and how much of the migration you want to run yourself.
What VoIP actually is
VoIP (Voice over Internet Protocol) means your phone calls travel over your internet connection instead of a dedicated phone line. The handset on your desk, the app on your laptop and the mobile in your pocket all register to the same system, so a call to your main number can ring all of them.
For a small business the practical difference is that phone numbers stop being tied to a building. You keep your 0117 or 020 number, and it follows whoever is meant to answer it.
Why 2026 is the year this stops being optional
Two things are happening at once.
The first is the deadline. James Lilley, Director of All-IP at Openreach, put it plainly in February 2026: "There's no time left to stall. The PSTN analogue network is obsolete, becoming harder to maintain and significantly more expensive to run."
The second is price. Openreach announced in November 2025 that Wholesale Line Rental, the copper product most analogue business lines sit on, would rise 20% from 1 April 2026, then 40% in July, then a further 40% in October. That takes a £10.65 rental to roughly double inside a single year. Waiting has a cost today, well before January 2027.
Worth checking too: your phone lines are rarely the only thing on copper. Card terminals, intruder alarms, lift emergency phones and door entry panels often share the same infrastructure, and they need their own migration plan.
The 2026 comparison: published UK pricing
Prices below are the vendors' own published figures, checked in August 2026. Where a vendor doesn't publish a UK price, we've said so rather than guessed.
- Microsoft Teams Phone: from £7.70 per user per month ex VAT on an annual plan. Suits businesses already on Microsoft 365. Calling minutes are a separate add-on.
- RingCentral: from £7.99 per user per month, up to £24.99. Suits a business that wants calls, video and messaging from one vendor. The headline figure is the entry tier on annual billing.
- Vonage Business Communications: £10, £15 or £25 per user per month. Suits small teams wanting tiers they can read at a glance. The feature gap between tiers is wide.
- 8x8: no published UK price. Suits higher call volumes and contact-centre requirements. Quote only, so allow time for procurement.
- Zoom Phone: listed in US dollars rather than pounds. Suits teams already standardised on Zoom. UK calling plans exist, but GBP pricing isn't published.
- 3CX: priced per simultaneous call per year, not per user. Suits teams where only a few people are on calls at once. Someone has to own the hosting and updates.
- Gamma Horizon: partner-quoted. Suits businesses wanting UK carrier backing with local support. Bought through a reseller, so compare the support wrapped around it.
Microsoft Teams Phone
If your business already pays for Microsoft 365, this is the first quote to get, because you're adding a phone system to software you own rather than buying a second platform.
Microsoft's UK pricing lists Teams Phone Standard at £7.70 per user per month ex VAT on an annual subscription. That's the system, without calling minutes. Adding UK calling takes it to £9.20 with pay-as-you-go minutes, £13.10 with 3,000 domestic minutes, or £26.10 with a domestic and international bundle. A Microsoft Teams licence is required alongside it.
The catch is that Teams Phone is a platform rather than a finished phone system. Call queues, auto attendants, number porting and emergency call handling all need configuring properly, and a badly built Teams Phone deployment frustrates people faster than the analogue system it replaced.
RingCentral
RingCentral's UK site puts its range at £7.99 to £24.99 per user per month. You get calls, video and messaging from one vendor, which keeps supplier management simple for a business without an internal IT team.
Read the small print on term length. The advertised figures assume annual billing, and the entry tier is thinner than most businesses expect once you look at call recording, analytics and integrations.
Vonage Business Communications
Vonage publishes three UK tiers: Express at £10, Core at £15 and Max at £25 per user per month. The tiering is easy to follow, which is genuinely useful when you're comparing quotes without a telecoms background.
Check which tier holds the features you actually need before you compare the entry price against anyone else's. The gap between Express and Max is wide.
8x8
8x8 no longer publishes per-user pricing on its UK site, so every conversation starts with a quote request. That's a reasonable trade if you need contact-centre capability, and an annoyance if you have 15 staff and want a number by Friday.
Zoom Phone
Zoom Phone is available in the UK with both metered and unlimited UK calling plans, and the unlimited plan covers calls to the Republic of Ireland. Zoom lists its flat-rate global calling plan in US dollars rather than pounds, so treat any GBP figure you see elsewhere as a reseller's price rather than Zoom's. It makes most sense for businesses already standardised on Zoom for meetings.
3CX
3CX prices per simultaneous call per year, not per user. For a 40-person business where six people are on the phone at any one time, that maths can be very favourable.
The trade is responsibility. Someone has to host it, patch it, and be on the end of the phone when a SIP trunk drops. 3CX has also revised its licensing tiers more than once recently, so take current terms from whoever is quoting rather than from a comparison guide written last year.
Gamma Horizon and UK wholesale platforms
Gamma is a UK carrier, and Horizon is sold through partners rather than direct. You're buying two things: the platform, and the partner's support wrapped around it. Those vary enormously, so ask the partner what their response times are and who answers at 8am on a Monday.
What the price lists don't tell you
Every provider above advertises a "from" price. Here's what sits underneath it.
Minutes are usually separate. A per-user licence often buys the system, not the calls. Ask for a quote that includes your actual monthly minutes, split between UK landline, UK mobile and international.
Contract length is where the discount lives. Published prices generally assume annual or 36-month commitment. Monthly rolling costs more, sometimes a lot more.
Handsets are capital, not licence. If you want desk phones rather than headsets, that's a one-off cost per desk plus provisioning time.
Porting takes longer than anyone quotes. Moving existing numbers to a new provider involves the losing provider, and it's the step most likely to slip. Start it early, and never cancel the old line until the port completes.
Emergency calls need a registered address. With a phone that moves between locations, 999 location data has to be configured, and it's a real safety obligation rather than a tick box.
Your broadband becomes your phone line. If your connection drops, so do your phones, unless calls fail over to mobiles. That failover is configurable on every platform here, and it's frequently left switched off.
How to choose without a telecoms background
Answer these before you take a single sales call, and the quotes become comparable:
- How many people need a phone, and how many are genuinely on calls at the same time? These are different numbers, and the second one changes which pricing model wins.
- What do you already pay Microsoft, and does your licence bundle include anything you'd be buying twice?
- Which numbers must you keep, and who is the current provider on each?
- What else is plugged into a phone line: alarms, lifts, card terminals, door entry?
- Who fixes it when it breaks at 9am on your busiest day?
- What's the total for year one including handsets, porting and setup, rather than the monthly per-user figure?
That last question is the one most quotes are built to avoid answering directly.
Where Inflection Point fits
We're an IT partner rather than a phone company, which means we don't have one platform to sell you. We design, migrate and support business phone systems on Microsoft Teams Phone, on UK wholesale platforms such as Gamma Horizon, and on 3CX, and we'll tell you which one your business should be on after we've looked at your call patterns and your Microsoft licensing.
The migration matters more than the platform. Number porting, call flows, handset provisioning and getting your alarm lines off copper are where these projects go wrong, and they're the parts a phone provider treats as your problem.
Inflection Point has supported UK businesses since 2010, we're trusted by 200+ UK businesses, and we hold Cyber Essentials Plus and UKAS-accredited ISO/IEC 27001:2022 certification alongside B Corp status. If you'd like the phone migration handled as part of a wider managed IT service, or you want an independent view before you sign a 36-month contract, our IT consultancy team can do that as a standalone piece of work.
For a fuller explanation of how hosted systems work, read our guide to cloud phone systems.
The one thing to do this week
Find out what your phone lines actually are. Pull your last telephony bill and identify every line, every number and every device attached to one, including the ones nobody thinks about. That inventory determines your options, your timeline and your cost, and it takes an afternoon.
If you'd like a second pair of eyes on it before the switch-off, book a discovery call and we'll go through it with you.
