Gamma
Business voice and connectivity.
What it means for you
Gamma is our connectivity and telecoms partner, providing the business-grade voice, VoIP and network services we design and manage as part of a joined-up IT service.
- Hosted VoIP and cloud telephony
- Business broadband and leased lines
- Reliable, scalable UK network
- Voice and connectivity managed alongside your IT
- FTSE 250Listed on the London Stock Exchange (GAMA)
- 1M+UK hosted phone seats on Horizon (end of 2024)
- #1UK SIP trunking provider by market share
About Gamma
Gamma is a UK business communications provider founded in 2001, headquartered in Newbury and listed on the London Stock Exchange’s Main Market as a FTSE 250 company. It reported revenue of £645.8m in 2025 and sells almost entirely through channel partners like us, which means its network is built to be delivered and supported locally.
Horizon, and voice inside Teams
Gamma’s Horizon cloud phone system passed one million UK hosted seats by the end of 2024, making Gamma the UK’s largest hosted voice provider, and Gamma was a launch operator for Microsoft’s Operator Connect programme, so calls can live natively inside Teams. Gamma states 99.999% platform availability for its core voice services.
The PSTN clock is ticking
The UK’s analogue phone network switches off in January 2027, taking traditional lines, and anything still plugged into them, with it. We migrate clients onto Gamma digital voice well ahead of the deadline, with numbers ported and call flows preserved, as part of one managed connectivity service.
The services this powers
Gamma, your questions answered
If Gamma provides the network, who do we call for support?
Us. Gamma is the carrier behind the service; we design, install and support what you use, and we deal with Gamma on your behalf. One number, one SLA, no carrier call queues.
What is Horizon?
Horizon is Gamma’s cloud-hosted phone system, used by over a million UK seats. There is no phone system box in a cupboard: calls, routing, voicemail and reporting live in the cloud, and staff can use handsets, laptops or mobiles interchangeably.
Can our phone system work inside Microsoft Teams?
Yes. Gamma was a launch operator for Microsoft Operator Connect, so full business calling can be delivered directly inside Teams while keeping proper call routing, hunt groups and reporting.
Want Gamma working for your business?
Book a free consultation and we’ll show you how it fits into a joined-up IT, security and print service.