SIP trunking - UK business lines

SIP lines offer a more flexible and lower cost alternative to ISDN for inbound and outbound voice calls.

Sip trunking London

SIP trunking is a standards-based replacement for traditional ISDN.

It connects your PBX to the PSTN via broadband, ethernet or private circuit into our national network.

Compared to ISDN our SIP trunking service is less costly per channel and more flexible in how and where geographic telephone numbers can be used. It’s also quicker to install and provision and, as standard, it delivers extremely robust business continuity.

SIP trunking world

Benefits of SIP lines

Save money on call costs and line rental

SIP delivers less costly, more reliable connectivity than ISDN over an IP connection. It can save up to 50% on line rentals and 25% or more on call costs.

Free internal calls and great features

Perfect for medium or large organisations with multiple sites, not only will you save on your line rental and call costs, but you’ll get free internal calls within your organisation and a whole host of great features.

Scale up and down when you want

SIP trunks are ideal if you are moving, upsizing or downsizing and want to keep your existing numbers. Scale up lines during busy periods and back down again afterwards. You can add lines, take them away, split calls at any time. You are always in control.

Built-in Business Continuity

SIP trunks can handle emergencies easily. They are inherently disaster recovery / business continuity ready, letting you reroute calls to an alternative location quickly and easily.

Compatible with Skype® for Business

Our SIP trunks are integration tested and approved to interoperate with Microsoft Skype® for Business, allowing you to directly connect to the platform to make external calls.

The service can support connections ranging from two channels for small PBX-equipped businesses to an unlimited number of channels for large enterprises and contact centres.
Our SIP trunks work seamlessly with each of the leading IP PBX brands in the UK market​

Interested in the Award-Winning SIP TRUNKING service?


The Award-Winning CLASSOUND

Wildix Classound was chosen as the Best International SIP service at UC Partner Awards 2021

The winners of the inaugural UC Partner Awards have been revealed, and Wildix are absolutely thrilled to announce that CLASSOUND: The Full Integrated VoIP Service for Local & International Calls was selected as the WINNER of the Best International SIP Service category.

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Based in central London, we specialise in finding the right voice and data solutions for small and medium size organisations.
If this is a perfect solution for your business, please Contact us.