ISDN Switch-Off: Preparing Your Business for VoIP - Fleximize

The ISDN Switch-Off: How to Prepare Your Business

BT is switching off its ISDN and PSTN networks in 2025. But what does this mean for SMEs?

By Damian Hanson

BT has announced it will be switching off its PSTN and ISDN networks in 2025 in favour of IP voice services, with a gradual phase-out of the older systems starting in 2020. At this point, BT will cease taking ISDN orders, and all businesses will be forced to find other IP-based options for their business telephony systems.

What are PSTN and ISDN?

PSTN (Public Switched Telephone Network) is the familiar landline telephone system originally set up for analog voice communication, and became the most reliable method of making voice calls and the main carrier for internet activity across the world. ISDN (Integrated Services Digital Network) then came along, allowing the digital transmission of voice, video and other services simultaneously, using the traditional PSTN network.

Why are they being phased out?

In short, these legacy systems are out of date, as are the associated maintenance and running costs. Despite having been updated radically over the decades since they were introduced, these lines are still essentially the same in setup and design as the original phone lines of the 1800s. With all other fields of technology advancing at lightspeed around us, it makes sense that our telecoms systems are also updated.

As of early 2017 there were still over two million businesses with an ISDN connection in the UK, all of which will be affected by the planned switch-off in the coming years. A 2017 survey revealed that a quarter of the UK’s businesses are still unaware that the switch-off is even taking place. These businesses need to be made aware of the upcoming changes so they can begin the necessary switch to voice-over-IP (VoIP) services to avoid finding themselves without a phone system.

What is VoIP?

VoIP allows people to make voice calls on a global scale using computer and mobile devices with an internet connection. The biggest and most noticeable difference between traditional ISDN and VoIP for business owners is the cost. Communications between VoIP users on the same network is often completely free, and setup and ongoing costs are massively reduced. These VoIP communication systems are also often referred to as cloud-based telephony systems.

Cloud and clear
Cloud and clear:

Businesses need to prepare for the switch from ISDN to VoIP phone systems

Future-proofing with cloud telephony

Businesses large and small need to modernize their communications systems to stay ahead of the coming changes. What many businesses don’t actually realize is how many benefits this modernization carries, particularly if they migrate to cloud telephony systems. Cloud telephony is a revelation for business communications in so many ways, and some newer systems are even more advanced and convenient than older VoIP services such as Skype.

Firstly, using cloud telephony significantly reduces business phone line and contract bills, as there is no line rental or contractual commitments for various services. It is also much simpler and easier to control than legacy systems. Like many SaaS-based tools, cloud telephony gives you and your team the ability to use your own devices to make business calls, add and remove users whenever needed and work from any location you want.

In a future where IP systems, BYOD and the gig economy look like dominating the business landscape, this level of flexibility in communications is essential to ensure businesses remain relevant and agile in the coming years.

Existing businesses: next steps

If you’re among the two million businesses that still have an ISDN connection, you should start thinking about switching to cloud-based telephony sooner rather than later. Here are some top tips to consider:

New businesses: how to future-proof your startup

If you’re in the process of setting up a brand new business, make sure you take the following points into account to prevent setting up an already outdated company:

Whether you’re an existing business or budding entrepreneur, making a move towards the cloud will help you stay one step ahead of the future of telecoms.


About the author

Damian Hanson is co-founder of CircleLoop, which provides cloud-based phone software to businesses. He previously co-founded One iota, a retail technology company, and oversaw its acquisition by the Sanderson Group Plc in 2013.