One of the UK's most widely deployed hosted VoIP systems. We look at what Horizon does well, where it costs more, and how it compares to the alternatives.
Gamma Horizon is a mature, well-supported UK hosted phone system used by tens of thousands of businesses. The underlying platform is reliable and feature-complete — desk phones, a desktop softphone and a mobile app on one number, with hunt groups, call recording and auto-attendant. Horizon is sold almost entirely through resellers, so your price, contract length and support experience depend on who you buy from. That is where a comparison helps: the same platform can vary by several pounds per user and by years of contract length between resellers.
Gamma Horizon is an app-based system, not a like-for-like replacement for BT One Phone's native SIM calling. If you need true FMC, see BT One Phone alternatives →
Gamma Horizon is a cloud-based hosted phone system from Gamma, a large UK communications provider. It runs on Gamma's own UK network, which gives it a strong reputation for call quality and reliability, and it is one of the default choices for UK small and mid-sized businesses moving off traditional lines ahead of the PSTN switch-off.
Horizon covers everything most businesses need: desk phones, a Windows and Mac softphone, and a mobile app, all sharing one business number. Features include hunt groups, auto-attendant, call recording, voicemail-to-email and call reporting, with a Collaborate add-on for video and messaging.
The important thing to understand about Horizon is that Gamma is a wholesale and channel provider — you almost never buy Horizon from Gamma directly. You buy it from one of hundreds of resellers, each of which sets its own price, contract length and support model on top of the same core platform.
Every Horizon licence includes a full set of business call-handling features. On top of that, a range of optional add-ons can be enabled per user as your needs grow — you only pay for the ones you use.
Add-ons are licensed per user or per agent and can be mixed across your team — for example call recording for compliance-critical staff, or call-centre agent and supervisor seats for a support desk. Tell us what you need and we'll include the right add-ons in your quote.
Horizon pricing is set by the reseller, so it varies. As an indicative guide for UK businesses in 2026:
| Plan | Typical price (per user/month) | Includes |
|---|---|---|
| Horizon (app / softphone) | From ~£9.99 | Business number, softphone, mobile app, core call features |
| Horizon with desk phone | From ~£12–15 | Everything above plus a supported IP handset |
| Collaborate add-on | From ~£3–5 | Video meetings, messaging and presence |
| Call recording | Included or add-on | Depends on the reseller package |
| Contract term | 12–36 months | Shorter terms available — worth asking for |
Pricing is indicative, based on publicly available information as of 2026, and excludes VAT. Always request a tailored quote for exact costs.
How Gamma Horizon compares to the main alternatives available to UK businesses:
| Provider | Contract | Pricing | Handsets | Support | Best for |
|---|---|---|---|---|---|
| Gamma Horizon reviewed | 12–36 months | From ~£9.99/user | Wide range | UK direct | UK SMEs needing SLA |
| GoYap recommended | 12 months | From £8.95/user | 300+ models | UK direct | Best value SMEs |
| 8x8 | 12–36 months | From ~£12/user | Wide range | UK support | Contact centre & multi-site |
| Vonage Business | Flexible | From ~£12/user | Wide range | UK/global | Integrations & flexibility |
| Microsoft Teams Calling | 12 months | From £12.50/user | Teams-certified | UK direct | Microsoft 365 users |
Gamma Horizon is a strong fit for UK small and mid-sized businesses that want a proven, reliable hosted phone system with good UK support and are happy with a desk phone plus mobile app setup. If reliability and a recognised UK network matter more to you than rock-bottom price, Horizon is a safe choice.
Because Horizon is sold through many resellers, the single most valuable thing you can do is compare a few quotes for the same platform — the price and contract length can differ significantly. If you want native SIM calling (as BT One Phone offered) rather than an app, or the lowest possible per-user cost, it is worth comparing Horizon against GoYap and Microsoft Teams Calling before committing.
Tell us about your business and we'll match you to the right solution — no obligation, and we compare Gamma Horizon against GoYap, Gamma, Microsoft Teams and more.
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