It’s the final countdown. Are you ready for the ISDN switch-off?


It’s the final countdown. Are you ready for the ISDN switch-off?



The ISDN and PSTN switch-off deadline is December 2025, and despite being reported for a number of years, many organisations are still yet to take action. A recent study found that over 50% of businesses are aware of the switch off but are yet to act, while only 1 in 10 organisations are appropriately prepared. It appears that many businesses are still happy to kick the can down the road for the time being. But is that wise?

For anyone operating with ISDN lines, it’s important to understand exactly what the switch off means for your business, the implications of failing to implement appropriate plans, and what steps you can take to prepare in advance of the deadline.

What is the ISDN switch-off?

Introduced in the 1980’s, ISDN or Integrated Service Digital Network, was rolled out across the country as a digital equivalent to existing PSTN (Public Switched Telephone Network) infrastructure. Much faster than traditional analogue lines, it allowed for the transfer of data alongside voice calls via a single copper line.

In 2015 however, BT announced that it was looking to switch off ISDN technology completely by 2025 as it was no longer deemed a suitable infrastructure to meet the growing demands of modern telephony. This process started earlier this year, and the full switch-off is still set to be completed in around 3 and a half years’ time.

What are the implications?

For those currently operating with ISDN phone systems, the short answer is that from December 2025 your existing phone lines will no longer be operational. This might seem like a while off yet, but with the process already underway your telephony is likely to be impacted sooner rather than later.

For starters, the quality of the service is likely to deteriorate as individual exchanges within the network are retired. From 2023 you’ll also no longer be able to purchase any additional ISDN lines, which will significantly hamper your flexibility as you enter the final two years of your service. As such it’s advisable that you make appropriate plans before 2023 and purchase any additional lines required so that you aren’t left short should you need to expand in the near-term.

There’s also some important considerations around support and security. With providers already looking beyond the switch-off to focus on new solutions, it’s likely that the levels of support for your service will be impacted as skills and resource are channelled in new areas. Some of your existing ISDN compatible hardware may also reach end of support before the deadline, and with no new replacements available you may be left to continue with legacy, unsupported and potentially vulnerable technology. Bad actors who may look to breach your network will be just as informed on these implications and may seek to exploit this as a vulnerable back door.

Cost will also come into the equation. Many organisations have preferred to stick with their current ISDN telephony in place of a modern alternative as the cost of their existing service represented good value in comparison. However, with the switch-off approaching, the price caps imposed by Ofcom on some of these services have been removed, leaving you at risk of unexpected price increases, especially as support and provision becomes more troublesome for telephony suppliers.

Leaving your ISDN running till the deadline could also put you in a difficult position with obtaining the support to migrate it. As with other IT deadlines that have passed in recent times such as Windows XP end-of-support, taking action at the last-minute puts you at the mercy of supplier availability to arrange an alternative solution. Is it worth the risk?

What are your options?

It’s crucial that if you’re operating with an ISDN system you look to make a change ahead of the switch off.

With traditional physical infrastructure facing retirement, a switch to an internet-based phone system such as VoIP is likely to be the best option. It’s the technology that all of the mainstream telephony providers are turning to as an ISDN alternative, and is set to become the standard following the 2025 switch off. This ensures that your telephony will be suitably future-ready for any new innovations coming down the line.

There’s a number of benefits for adopting a VoIP system, all of which can be realised well in advance of the ISDN switch off. An internet-based phone system delivers unprecedented levels of flexibility when compared to a more traditional system. New lines can be implemented in minutes, with the service scaled up and down as needed to meet the demands of your business.

Facilitating calls over the internet also removes the need for physical on-premises infrastructure which in turn reduces the overall cost of your telephony as there’s no longer a requirement to manage and maintain physical hardware.

You’ll also be better placed to facilitate remote or flexible working. Many VoIP solutions are delivered to users via a soft phone client or desktop application which can be engaged from anywhere without the need for a physical connection or handset. Internet phone systems can also be managed via a simple management portal that provides a level of self-service for call management, number allocation, and other helpful features such as analytics and call recordings.

We’re here to help

Changing your telephone solution can seem like a significant undertaking, even more so when a firm deadline for your existing service is approaching.

We’ve already helped a number of customers make a change to their telephony solution, so our expert team are well prepared to manage your switch and remove unwanted complexity.

Crucially, we’ll work with you to identify your unique requirements and advise on the solution that’s best aligned with your needs, so you can make an appropriate long-term choice as part of your wider IT strategy.

There’s also real value in looking to proactively make a switch ahead of time to alleviate any additional challenges that could be encountered closer to the deadline.

To learn more about the implications of the ISDN switch off, and the potential options available for your business, get in touch with the team.