With the phased shutdown of the Public Switched Telephone Network (PSTN) and Integrated Services Digital Network (ISDN) set to conclude in 2027, new research from Zen Internet has revealed that UK businesses are alarmingly unprepared for the transition.

The study found that only 18% of small businesses and a quarter (26%) of large businesses currently have a post-PSTN solution in place. With enterprise and SME results combined, 27% are assessing their options and 17% of businesses are yet to work out what their next steps will be. Nearly a fifth (19%) are currently migrating to another system.

Even more concerning, nearly one in ten (9%) remain unaware of the impending ‘landline’ network switch off entirely.

A looming deadline: act now or face disruption
The Public Switched Telephone Network (PSTN) is an analogue system using copper wire, usually known as the landline. The Integrated Services Digital Network (ISDN) allows digital services to be transmitted via PSTN.

The transition to an all-IP (digital) network marks a significant technological shift, with businesses relying on PSTN services potentially facing major connectivity challenges.

Moreover, the 2027 deadline could catch businesses out. After December 2025, businesses could receive just 90 days’ notice to migrate to all-IP solutions or risk losing access to essential communication and operational systems.

David Barber, Strategy Director at Zen, highlights the disconnect between awareness and action among UK businesses relating to the switch off. He says:
“While our research shows good awareness that the switch off is happening there’s a clear disconnect between knowing about the end of PSTN and having a future-proof solution in place. Too many businesses may be leaving decisions around all-IP communications to the last minute, which could be a recipe for disruption.”

The risks of delaying migration
There are several reasons to start considering switching to all-IP connectivity and communications sooner rather than later.

The PSTN network is starting to creak, with the old technology becoming increasingly difficult to maintain. Customers on PSTN are already experiencing increased downtime, and the situation is only likely to get worse as the switch off gets closer.

Businesses that fail to transition to a digital solution before the deadline could lose phone connectivity altogether, as well as their phone number and other systems such as security, payments, IoT devices that rely on it. A rushed last-minute migration could lead to poor decision-making, with businesses adopting new solutions that fail to meet their unique needs.

Barber advises:
“There’s no need to panic, but preparation is key. Businesses should start thinking about the options open to them now. Check what’s available in your area, conduct an audit of all systems that rely on the old network, and talk to your technology partners. At Zen, we’re always happy to run through what PSTN means for our customers.”

The benefits of acting early
Transitioning to all-IP not only ensures continuity but opens new opportunities for enhanced features and flexibility in communications. Early adopters can gain a competitive edge by leveraging the benefits of digital technology sooner.

Barber concludes:
“Making the switch ahead of the deadline not only mitigates risks but positions businesses to unlock the full potential of all-IP services. With the right preparation, this shift can be a growth opportunity rather than a challenge.”

For more insights, download Zen’s white paper, The Great British Switch-Off.