The PSTN switch-off is nine months away. By January 2027, BT will have decommissioned the UK's traditional telephone network entirely, and every business still running on ISDN or analogue lines will lose service. That deadline is concentrating minds, and it should. But the forcing function is also an opportunity: hosted PBX systems in 2026 are genuinely good, significantly cheaper than legacy systems, and far easier to manage. The question is which provider to trust.

Key takeaways:

  • 3CX - best value for SMEs; concurrent-call pricing rather than per-user means costs stay flat as headcount grows
  • Gamma Horizon - best UK-native option; 200+ CRM integrations, four mix-and-match tiers, strong partner support
  • bOnline - cheapest entry point at £7/user/month, setup in under 5 minutes; suits micro-businesses and sole traders
  • Dialpad - best for AI features; call transcription, coaching, and sentiment analysis built in from £12/user/month
  • 8x8 - impressive features but a Trustpilot score of 2.0/5 reflects persistent support problems; approach with caution
  • RingCentral - solid enterprise choice; UK Trustpilot is 4.3/5 but global score is 2.6/5, suggesting patchy support outside the UK

Why 2026 Is the Year to Decide

Every UK business must switch to a VoIP-based system before January 2027. There is no extension. BT confirmed the PSTN/ISDN switch-off date, and businesses that delay decision-making risk a rushed migration with limited provider choice and higher costs.

The good news is that hosted PBX - where your phone system runs in a provider's cloud rather than on hardware in your office - is mature, affordable, and well-supported in the UK market. Cloud-based systems typically cost £8-25 per user per month, compared to £35,000-50,000 for a legacy on-premise PBX installation. Over three years, businesses switching to cloud VoIP typically save around 50% on communication costs.

How Hosted PBX Pricing Works

Most providers charge per user per month. This is predictable but can get expensive as teams grow.

3CX takes a different approach. It licenses by concurrent calls rather than headcount - meaning a 100-person business where only 10 people are ever on the phone simultaneously pays for 10 lines, not 100 users. For businesses with many staff but moderate call volumes, this model cuts costs by 80-85% compared to per-user providers. A 75-person team on 3CX typically pays around £3,400-4,400 per year; the same team on RingCentral would pay approximately £22,500.

Understanding which model suits your call patterns is the single most important pricing decision you'll make.

The Main Providers Compared

Provider Pricing model Starting price Trustpilot Best for
bOnline Per user/month £7.00/user 4.3/5 Micro-businesses
Gamma PhoneLine+ Flat monthly £8.95/month 4.9/5 (Google) Simple landline replacement
Gamma Horizon Per user/month £9.95/user - UK SMEs, hosted UC
Dialpad Per user/month £12.00/user 4.4/5 AI-focused teams
RingCentral Per user/month £12.99/user 4.3/5 (UK) Mid-to-large enterprise
Vonage Per user/month £18.00/user 4.5/5 Integration-heavy orgs
8x8 Per user/month £19.00/user 2.0/5 Global enterprises
3CX Concurrent calls £195/year 3.9/5 SMEs with high headcount

Best Value for SMEs: 3CX

3CX is the strongest value proposition for UK SMEs in 2026, rated 9.7/10 by T2K Voice and Data and 4.5/5 on Capterra from 254 reviews.

The concurrent-call licensing model is the key differentiator. Businesses with 30+ staff but relatively low simultaneous call volumes will pay a fraction of per-user competitors. Setup is quick for smaller deployments, and the platform covers voice, video, team chat, and contact centre features.

The tradeoff is technical overhead. Larger deployments benefit from a reseller or IT partner, and the mobile app has drawn criticism for occasional glitches. 3CX is not a plug-in-and-forget system. But for businesses with basic IT competence - or a managed service partner - the savings justify the involvement.

Best UK-Native Option: Gamma Horizon

Gamma Horizon is rated 9.5/10 and sits at £9.95-17.95 per user per month across four mix-and-match tiers. It is built specifically for the UK market, offered through a network of partners who provide local support and implementation.

The standout feature is 200+ CRM integrations - useful for businesses that want calls logged automatically in Salesforce, HubSpot, or similar platforms. Mobile apps are included for remote and hybrid workers. The cloud-only architecture means no on-premise hardware, which simplifies management.

Gamma also offers PhoneLine+ at a flat £8.95/month - a simpler product designed purely as a landline replacement. It lacks the depth of Horizon but is the most frictionless path for small businesses that just need to port their number and stay operational post-switch-off.

Cheapest Option: bOnline

bOnline is the lowest-cost hosted PBX in the UK market, starting at £7.00 per user per month and topping out at £15.50. Setup takes under five minutes, and 84% of its 4.3/5 Trustpilot reviews are five-star.

It is designed for freelancers, sole traders, and micro-businesses that need a professional phone presence without the complexity or cost of enterprise systems. Voicemail-to-email is included, desk handsets are available on upper packages, and there are no hidden fees.

bOnline is not the right choice for businesses that need advanced call routing, contact centre features, or deep CRM integration. For those that do not, it is hard to beat at this price.

Best for AI Features: Dialpad

Dialpad has positioned itself as the AI-first business phone system, and the claims are substantive. Its built-in AI provides real-time call transcription, post-call summaries, sentiment analysis on customer calls, and live coaching suggestions for sales and support teams.

Pricing starts at £12/user/month, rising to £20 for the Pro tier. The 4.4/5 Trustpilot score reflects a strong product. The caveat is that the most compelling AI features are locked to higher-tier packages, so budget carefully if AI analytics is the reason you're choosing Dialpad.

For businesses where call quality, conversion, and coaching matter - sales teams, customer service operations, client-facing professional services - Dialpad is the strongest differentiated choice in this market.

The Enterprise Choice: RingCentral

RingCentral is the best-known name in cloud business communications and remains a solid choice for larger UK organisations. UK pricing runs from £12.99 to £29.99 per user per month; contact centre (RingCX) starts at £52/user/month.

Its UK Trustpilot score of 4.3/5 is reasonable. The platform handles voice, messaging, video (up to 200+ participants), and SMS in a unified interface with 300+ native integrations. RingSense AI handles call transcription and translation.

The warning is the global Trustpilot score: 2.6/5. Support quality appears to degrade outside the UK. For businesses with international operations, this is a risk worth factoring in.

The One to Approach with Caution: 8x8

8x8 scores well on features - global coverage across 120 countries, advanced analytics, omnichannel support - but its 2.0/5 Trustpilot score from 428 reviews is the worst of any major provider in this market. Recurring complaints centre on customer support responsiveness.

Pricing starts at £19/user/month and rises to £135 for enterprise tiers. For businesses with genuine international operations and a dedicated telecoms manager to handle issues, 8x8 is functional. For SMEs that need responsive support, it is a poor fit.

Frequently Asked Questions

Q: What is hosted PBX and how does it differ from a traditional phone system? A hosted PBX system runs in a provider's cloud rather than on hardware in your office. Calls are routed over the internet, and all features (voicemail, call routing, auto attendant) are managed by the provider. A traditional PBX requires on-site hardware, physical maintenance, and typically a significant capital investment.

Q: Do I have to switch phone systems before the 2027 PSTN switch-off? Yes. BT's PSTN and ISDN networks will be decommissioned by January 2027. Any business still on these networks will lose service. Migrating to a hosted PBX or VoIP system is required, not optional.

Q: How much does hosted PBX cost for a UK business? Most providers charge £8-25 per user per month. A 10-person business typically pays £80-200/month. 3CX uses concurrent-call pricing rather than per-user, which is significantly cheaper for larger teams with moderate call volumes - around £195-1,195 per year regardless of headcount.

Q: Can I keep my existing phone number when switching to hosted PBX? Yes. Number porting lets you move your existing geographic (01/02) or non-geographic (03/08) numbers to a hosted provider. Most providers handle porting as part of onboarding. Allow 2-4 weeks for the process.

Q: Which hosted PBX provider has the best customer support in the UK? Based on Trustpilot scores, Gamma PhoneLine+ (4.9/5 on Google), bOnline (4.3/5), Dialpad (4.4/5), and Vonage (4.5/5) all have strong support reputations. 8x8 (2.0/5) and RingCentral's global score (2.6/5) are the notable weak points.

Q: Is 3CX right for a small business with no IT team? It depends on deployment size. For a small deployment (under 20 users), 3CX can be set up by a non-technical owner with some patience. For larger or more complex setups, using a 3CX-certified reseller is strongly recommended. The cost savings typically cover partner fees comfortably.

The Verdict

For most UK SMEs in 2026, the choice narrows to three options:

  • bOnline if you want the simplest, cheapest system and your needs are basic
  • Gamma Horizon if you want a UK-native hosted solution with proper partner support and CRM integration
  • 3CX if your team has 30+ people and moderate call volumes - the concurrent-call pricing model will save thousands per year

RingCentral and Dialpad are strong for larger organisations with specific needs. Vonage suits businesses that live in their CRM. 8x8 is worth avoiding unless you have very specific global requirements and the internal resource to manage support issues yourself.

The PSTN switch-off removes the option of doing nothing. The upside is that the hosted PBX market has matured to the point where all the leading options work well - the decision is mostly about matching pricing model, support quality, and feature depth to your business.