Business after ISDN – counting down to the 2025 switch off

Posted 16th May 2019 under News

The countdown to the ISDN and PSTN switch off, planned for 2025, is underway. And although the lines themselves won’t cease until 2025, BT will stop supplying them in 2023.

Over the coming five years, this will affect many businesses. While for those with plans to replace their systems anyway, this will be a cost and consideration that has already been factored in, for businesses with ISDN lines that aren’t immediately in need of upgrade or replacement, this will be an additional and unplanned investment. Whether you are planning to invest now, or nearer to the 2025 deadline, though, it’s well worth checking out the alternatives now.

What is ISDN and who uses it?

ISDN – or Integrated Services Digital Network – was the first high-speed internet service, delivering fast, constant data speed and efficient internet access via a phone line and revolutionising the online industry. It is, basically, a telephone-based network that operates on a dedicated line, allowing the transmission of data and phone conversations digitally over normal telephone wires.

ISDN – when it was introduced – was great for business, allowing the subdivision of one incoming line into a number of channels, so that multiple calls could be made from it at any one time.

Figures from 2017 suggest that there were over two million businesses using ISDN lines then. While this number is likely to be less now, it will still be significant.

So how do you know if your business uses ISDN lines? If your business phone calls are handled by a Private Automatic Branch Exchange (PABX), they are likely to be connected to the telephone network via an ISDN line.

What is PSTN?

PSTN – or public switched telephone network – is the traditional telephone line network that carries analogue voice data over copper lines. It’s a technology that, while it has been improved greatly over the years, is almost exactly the same as it was when telephone was first networked in the late 1800s.

Why replace ISDN?

Both ISDN and PSTN are incredibly old fashioned legacy technologies, and both come with associated maintenance costs and drawbacks.

What’s more, as the roll out of fibre optic services continues across the UK, many of the advantages that ISDN offered have been superseded. In fact, ISDN can prove expensive if, for instance, there is a requirement to extend call capacity and additional lines need to be installed.

The UK isn’t alone in replacing ISDN: at the end of 2018, Germany was one of the first countries to close their Integrated Services Digital Network.

Hosted VoIP – the future proofed alternative to ISDN

Luckily, there are proven technologies ready to step in to the space left by ISDN. Hosted Telephony – or Hosted VoIP as it’s often called – is a telephone system that’s located in a data centre hosted on the Cloud. With VoIP, your calls are made using IP handsets, in exactly the same way as they would on a PBX network. They are delivered, though, via broadband to the ISP network, where they are routed out as usual.

Hosted VoIP is one of the most popular solutions in the marketplace. Back in Autumn 2017 Cavell reported that the UK Hosted VoIP market had already hit over 3 million users and was the European leader in terms of numbers of Hosted VoIP users.

It has clear benefits:

VoIP systems are quick and cost-effective to roll out, with no capital outlay required. What’s more, hosted telephony enables flexible working, allowing users to move their desk phone – together with the number associated with it – to other locations.
VoIP systems are truly scalable, with new lines easy and cost effective to add, growing with your business, rather than holding it back.
VoIP systems allow you to divert your number to a mobile whenever you are not at your desk, which is great for field workers and even better for disaster recovery.
VoIP systems offer space savings too, with no requirement for large and expensive on-site equipment. That means there are no maintenance packages needed for hardware either!
What do you need to do now?

High speed Broadband, whether Ethernet or BT’s fibre roll-out, is essential for the UK-wide ISDN switch off because it is essential for a successful VoIP connection. So, while BT has announced 2025 as the great ISDN switch off, this will, we’re sure, be very much dependent on Broadband being up to speed.

If your system is still running effectively, 2023 doesn’t mean that your existing systems will not be supported. The lines you use will still be in operation until 2025, giving you two more years to explore the alternatives – especially useful if your business is in an area with poor Broadband coverage.

If your current contract is due for renewal, or your hardware is coming to the end of its life, though, now is the time to start considering the benefits of VoIP as, after 2023, you won’t be able to buy any PSTN or ISDN systems.

Step ahead with Hosted VoIP from Cambridge Telecom

At Cambridge Telecom, we offer two Hosted VoIP telephony packages – Daisy’s HV.Select and Vodafone’s One Net Business. Whenever your business is ready to make the change from ISDN to Hosted VoIP, we will work with you to build the most effective telecoms solutions for your business.

Find out more about Hosted VoIP from Cambridge Telecom today. Please call our sales team on 01223 661636 or email us at