With ISDN and PSTN network switch-off is scheduled for 2025, it’s important for UK businesses to future proof.

It may be the UK’s best-kept secret this year. Coronavirus, Brexit negotiations and the future of work have taken over our social media platforms as of late, but another revolution is quietly happening in the UK telecoms industry – the closure of its PSTN networks and a transition to all-VoIP networks – and it began in 2020.

End of PSTN/ISDN: What's the time frame?

We’ve collected a quick FAQ on the PSTN/ISDN shut down and what it means for local businesses:


What is happening with the 2025 network switch-off?

From 2020 onwards you will no longer be able to purchase integrated services digital network (ISDN) and public switched telephone network (PSTN) circuits in the United Kingdom. As of 2025, the PSTN circuits will be shut off completely. This is a major step towards the United Kingdom’s mass IP-network migration, with VoIP core networks set to replace all of the outdated legacy technology.


What is ISDN?

Integrated service digital network (ISDN) was the first iteration of digital connectivity. ISDN first appeared in the 90s and revolutionised internet connectivity. Many people credit technology as being the groundwork for modern, faster internet solutions.


What is PSTN?

The public switch phone network (PSTN) is what you might refer to as the classic analogue telephone system—the system that enables landline connectivity. This centuries-old technology was introduced during the 1800s and allows for information to be transmitted through a network of copper wires. Businesses have been using PSTN as their primary method of transmitting phone calls and fax transmissions for many years. PSTN is still the foundation of their communications for millions in the UK, which poses a business continuity risk as the country migrates to an all-VoIP environment.

VoIP Business Phone System

Why are the telecoms providers migrating everyone to VoIP all of a sudden?

The move comes as part of cost-saving efforts from national telecoms to stop supporting legacy technologies. By switching to all-VoIP, telecoms providers only have to maintain one network, which is much cheaper for them. It’s estimated that over 2 million local UK businesses will be impacted by the switch off. The biggest impact will be felt by those who are still using fax machines or landline telephones. UK businesses will need to look for alternative methods to maintain communications coverage.


Who will be affected?

The UK 2025 Switch-off will impact all businesses currently operating on ISDN or PSTN telephony. The switch-off will affect a large volume of small businesses, as 42% of SME’s report that they still use analogue lines to transmit data. That’s around 2.4 million businesses in the UK. And, while larger enterprises have already updated their systems, not all have made the switch. Roughly 33% of larger firms still operate on ISDN or PSTN for telephony. If your business falls into this category, then the UK 2025 switch off will have consequences for your operations.


Options for UK businesses in the face of this shutdown:

Many telecoms’ operators (such as Trio Telecom) are encouraging customers to consider voice over the internet protocol (VoIP) for their telephony. How VoIP works for your phones and fax machines is simple. Using an adaptor device, you can upgrade your landline-reliant fax machines and phones into hardware with internet connectivity, or you can replace your phone system with a Hosted Voice solution.

In essence, VoIP means you can use your current devices to send information to other devices, via the internet. The result is minimal change to your systems while maintaining communications coverage, even after the UK 2025 switch off!

If you’re concerned with how your business will be impacted by these coming changes, contact our team for support. We are experts in practicing the art of telecoms and would love to support you where we can!