SIP trunking for simple, scalable Internet calling

SIP trunking is the simplest way to way to connect your phone system to the Internet, empowering you with low-cost, highly scalable calling capability.

With ISDN lines due to be switched off in the UK in 2025, now is the time to look to your future with VoIP solutions such as SIP. At Content+Cloud we offer cost-effective, cloud-based, global SIP trunking that will allow you to easily manage calling from your communication platform or phone system.

What is SIP trunking?

SIP (session initiation protocol) is a type of VoIP (voice over Internet protocol) standard that allows you to run and manage voice, video and messaging ‘sessions’ digitally. SIP trunking connects your private branch exchange (PBX) to the Internet, like a digital version of a landline. It’s becoming the industry standard for enterprise VoIP calling.

Whether set up on premises or hosted virtually, SIP trunks can hold huge numbers of lines – called channels – to connect your users via any enabled desktop or mobile device.

Choose future-ready, flexible calling with a SIP trunk service

Telephony is a critical part of how service-driven organisations communicate with customers. A reliable phone system is therefore fundamental if you’re to deliver the level of customer service you promise.

But older technologies can be expensive and time-consuming to maintain, reconfigure and move. If you’re expanding, downsizing or setting up services in new countries, traditional phone systems can slow down your progress.

SIP trunking is the ideal solution if you’re looking to move from an analogue PBX to an IP version. There’s no need to switch carriers and, if you’re using cloud-based SIP trunking, there’s no huge capital outlay on new equipment required. But it’s also a choice move if you’re communicating digitally via ISDN, which is to be phased out in the UK by 2025.

What we offer as your SIP trunk provider

At Content+Cloud we offer cloud-based SIP trunking that allows you to deliver powerful unified communications that are globally available and flexible to your future needs. We’ll work with you to understand exactly what your organisation requires, such as channels and minutes plans, new and existing phone numbers, system configuration, infrastructure and routing.


All media, all locations

SIP trunking gives you one line for voice, instant messaging and video, making it the perfect underpinning technology for unified communications and collaboration. Your services will be available to users and customers in any location, on any device.


Get started quickly

We’ll get your phone system online at speed. You can bring over your carrier and devices – and if you need to keep your phone numbers, we can port those over too. And as our SIP trunking is done in the cloud, you won’t need to invest in additional hardware.


Reliability and flexibility

Virtual SIP trunking means no more maintenance and upgrade costs for on-premises networks. There are no need physical lines, so if you need to scale things up, you can add more channels easily.

Organisations who’ve chosen us as their SIP trunk provider

At Content+Cloud, we live+breathe client success. We work with ambitious organisations of all sizes and sectors to deliver digital transformation. Enterprise software, food and financial service companies are among those we’ve helped with our SIP trunk service.

Let’s talk about how our SIP trunk service can help you 

Supporting you beyond SIP trunking

At Content+Cloud we’re more than a SIP trunk provider – we provide end-to-end, expert support across all voice and data services.

If you’re looking to create greater experiences for your users and customers through calling and unified communications, here are just a few of the areas where we can help.


Whatever your organisation’s size and services, you’ll require business connectivity that guarantees speed, security and reliability. Our dedicated Connect Team can ensure that you adopt the right type of services at the most cost-effective price.

Find out more about our connectivity services 

Cloud phone systems

Cloud phone systems give you the benefits of enterprise-standard telephony without the hassle and cost of traditional networks and devices. We can help you get up and running with technical and managed support.

Find out more about cloud phone systems 

Teams Voice services

We can give you end-to-end Teams Voice services, including advice on plans and direct routing. And through our Sipcom HALO Platform cloud architecture solution, we can give you global coverage with phone numbers in 120 countries.

Find out more about our Teams Voice services 

Contact Centre as a Service (CCaaS)

We can provide a CCaaS solution that combines HD voice quality and advanced PBX-style functionality with the security and flexibility of the cloud. We’ll work with you to understand your environment, users and customers and deliver a service that fits quickly and seamlessly with your chosen interface.

Find out more about CCaaS 

Market-leading expertise in Microsoft Teams

Content+Cloud is the only Microsoft Partner to be able to offer you a complete end-to-end solution for Microsoft Teams calling.

We have some of the foremost experts and MVPs (Microsoft Most Valuable Professionals) with experience in Microsoft Teams, communications, messaging, enterprise mobility management, and collaboration and content.

You can rely on the highest-quality advice and managed services from the people who know Microsoft best.

Find out more about our Microsoft Teams services