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Gamma SIP Trunks

SIP Trunking is rapidly replacing legacy telephony services (ISDN) for inbound and outbound voice calls. Gamma is the UK’s leading SIP Trunks provider. Our SIP Trunks connect your site’s on-premise telephone system directly into the Gamma network via an internet connection to carry and terminate your calls across the public telephone network.

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Reliable voice services and instant call management with flexibility and continuity.

Our SIP Trunks and Inbound call management solutions take SIP beyond a connectivity service into a world of multi-feature applications, putting you in control.

Personalise how you communicate with Gamma SIP Trunks.

Any business with a PBX can switch to our SIP trunking service and immediately benefit from a more flexible, less expensive and more resilient phone service.


Why Gamma?

UK's number 1 SIP Trunks provider

Over the past 20 years, Gamma has led the way in cloud-first communication solutions. As the UK’s top SIP provider, we empower one in three UK businesses with cloud voice services. Leveraging our SIP Trunking heritage, we’ve become experts in enabling voice for Microsoft Teams Phone. Our flexible solutions are tailored to diverse business needs, and our services are trusted across various Government and Public Sector organisations.

Full PSTN breakout with Gamma SIP

SIP Trunks with flexibility

Built in resiliency with Gamma SIP

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Benefits of Gamma SIP Trunks

Business continuity & disaster recovery

Protect your office environment with Gamma SIP Trunks in the event of emergencies like fire or flood. Easily reroute calls from affected branches to alternative locations at no extra cost.

Ensuring continuous service availability is simple by connecting two on-premise telephone systems, each situated at a separate location. In the event of one site experiencing downtime, inbound and outbound calls seamlessly reroute to the second site instantly and without incurring any costly call-forwarding fees.

Combine with our Inbound service for absolute resilience, instantly redirecting inbound calls to any destination if SIP Trunking services are unavailable.

Multi-site rationalisation

Handle seasonality and relocation with ease

Compatible with business networks and apps

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Smart working with Gamma SIP services

Save money, work flexibly and collaborate better with a range of features.

Free UK calls and fraud protection

Business-grade voice and internet convergence

Phone Lines and PBX estate rationalisation

Award winning, 24/7, UK based support teams.

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ISO27001 certification and use of Tier 1 data centres.

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Instant Business Continuity and Disaster Recovery built in.

Full integration with existing business networks

Guaranteed uptime of 99.999% & industry leading SLA's.

Frequently Asked Questions About Gamma Gamma SIP Trunks

How resilient is SIP trunking?

What is the difference between SIP trunking and VoIP?

Is Gamma SIP secure?

Is Gamma SIP compliant with PCI DSS?

How good is call quality with SIP Trunks?

What if we want to move offices?

Can we add or remove lines?

How can we help you?