Get ready for the ISDN switch-off – our handy guide

Posted 19th Feb 2020 under News

A handy guide to the 2025 switch off, what does this mean?

With the new decade upon us, the final chapter for ISDN has begun. Here’s an update on what’s happening, with some key dates for your diary, along with action points to consider if you need to find an alternative.

It was back in 2017 that BT announced the coming demise of the Integrated Services Digital Network (ISDN). Once the gold standard in voice and data transmission, it’s now a dinosaur in our brave, new world of super-fast fibre broadband. With traditional, fixed-line telephony rapidly becoming a thing of the past, the extinction of ISDN has become inevitable.

The ISDN switch-off timeline

The phase-out of ISDN is concurrent with that of the UK’s Public Switched Telephone Network (PTSN). Using analogue voice data, the PSTN has been left behind by the digital communications revolution. The equipment which runs the PSTN is ageing and has effectively become obsolete.

There are two key dates to bear in mind with regard to the forthcoming ISDN switch-off:
September 2023 BT Openreach will no longer supply new ISDN lines.
December 2025 ISDN will be withdrawn completely.

Replacing ISDN – when to make your move
If you’re one of the two million or so businesses that are affected by the ISDN switch-off, you’ll need to find an alternative solution, sooner or later.

Is your telephony contract coming up for renewal? Do you need to update or upgrade your communications hardware? If so, now could be a good time to install an effective ISDN replacement.

Even if you’re still in contract, it still might be a wise move to line up a replacement for ISDN right now. That way you can ensure a smooth transition and make sure your communications systems are future-proofed. Remember, if you need more capacity, as of September 2023 you won’t be able to order additional ISDN lines.

Hosted VoIP – the perfect solution
Voice over Internet Protocol (VoIP) is not just the natural successor to ISDN. It also offers significant advantages. Hosted VoIP solutions provide advanced functionality and easy scalability without the necessity to invest in costly hardware or network infrastructure. Because they’re hosted in the Cloud, VoIP systems are also quick and cost-effective to deploy.

By switching to VoIP you’ll benefit from the true flexibility of integrated communications, with the capability to manage calls via PCs and mobile devices, as well as traditional phone handsets. Advanced features include instant messaging, video conferencing, call forwarding, automatic call routing, call transfers and three-way calling – all configurable through a user-friendly online portal.

Here are just some of the other benefits of Hosted VoIP:
• It’s easily transferrable if you’re relocating your business.
• Having one single network for voice and data can reduce your line rental costs.
• It enables the use of non-geographic phone numbers.
• It’s ideal for home-based and remote workers.

At Cambridge Telecom, we offer two industry-leading Hosted VoIP telephony packages: Daisy’s HV.Select and Vodafone’s One Net Business. We can deliver the ideal solution for all types and sizes of business, from SMEs to large corporations with multi-site networks.

To find out more about Hosted VoIP from Cambridge Telecom, call our sales team on 01223 661636 or email