2025 still seems quite a long way off, which is why a large number of small businesses are either unaware of the end of ISDN or unprepared for it.

There’s no great rush and certainly no need to panic, but every business should at least be aware of what’s happening in 2025 and what it will mean for them. Forewarned is forearmed, and four years will pass more quickly than you think.

So the first thing to know is that in 2025 BT is switching off the ISDN telephone network for good. From that moment on, all your telephone calls will be made over the internet.

That may not sound like such a big deal, but it’s the most fundamental change to telecoms infrastructure in the UK since the 1980s, when ISDN was first introduced. In effect, it means the end of the era of the “landline”, and its final replacement with Voice over Internet Protocol services, usually known as VoIP.

And there’s probably no getting out of it. If you’re still using ISDN at the end of 2025 you will be forced to migrate to a VoIP service. BT has been talking about this switch-off date for a number of years, so it’s unlikely that the deadline will be extended.

Why is BT shutting down ISDN?

So why is 2025 happening at all? After all, many businesses are quite happy with their ISDN services.

When ISDN was first introduced in the 1980s, it was revolutionary. For the first time, voice and data could travel over the same line. But this was before the advent of unified communications, video calling, conferencing and more. The arrival of modern, internet-based communications has stretched the ISDN network to the limit.

The fact is, the ISDN network struggles to cope with the communications demands of modern business. On top of that, the ageing network is costing more and more each year to maintain and repair. That’s important, because the ISDN network is about more than just telephony. Everything from your ePOS system and alarms to your CCTV could be connected via ISDN, making the switch to a more reliable network even more important.

VoIP is the future

In addition, there is now a more than capable replacement for ISDN. Back in the early 2000s, the first incarnations of Skype and other internet-based voice services were unreliable and prone to drop outs.

But since then VoIP calling has been massively improved. The advance of bandwidth and broadband speeds means that internet-based calling is now efficient, reliable and cost-effective. VoIP can not only do everything ISDN can do, it can offer businesses a lot more besides.

For example, unified communications can put all your communication needs – voice, video, chat, email, etc – in one package, while cloud-based systems let you access your phone system from anywhere, on any device.

They let you make and take professional business calls wherever you have an internet connection, using the same telephone number and benefitting from all the call management features that were previously only available in the office.

The business benefits of all this are potentially huge. If you’re transitioning to a remote or semi-remote (hybrid) workforce, VoIP makes equipping workers with a permanent, work-from-anywhere telephony solution easy. Unified communications lets dispersed teams communicate in a variety of ways (and customers can do the same) and collaborate in real time. Even the most basic VoIP services are flexible and easily scalable, letting you add or remove users with a couple of clicks.

All this makes VoIP highly cost-effective. Internet calls are cheaper than standard ISDN calls anyway. In addition, hosted VoIP systems allow you to ditch the time and expense associated with housing, protecting and maintaining an in-house PBX.

We can help you go all-IP

So there are big benefits to VoIP over ISDN, but that doesn’t mean you need to switch today. If you’ve invested in an ISDN telephone system and it gives you everything your business needs, there’s no point rushing into a major investment.

But if your current telephone system is nearing end of life, or your communication needs are changing (perhaps due to new hybrid working patterns), it’s worth noting that only VoIP can future-proof your business for 2025 and beyond. Switching to VoIP now means you don’t have to worry about it later, when the deadline is looming. It also means you can start benefiting from all-IP telephony straight away.

Whichever you choose, we’re on hand to help. Express Telephony offers a free IT and telecoms audit to businesses throughout southern England to make sure you have the right infrastructure for your needs, and that you’re not paying more than you need to. We take the time to get to know your business and we’ll never try to sell you a solution you don’t genuinely need.

If you do want to switch to VoIP, our experts have decades of experience in helping businesses get better value for money and the right level of technology, offering a level of in-depth, patient support you’ll never get from a big name ISP. We’ll take you through every step, explaining exactly what’s happening, when, how and why, in a way that’s always easy for you to understand.

So what is the 2025 switch-off? At heart it’s the realisation that old telephone technology isn’t fit for modern communications. Quite simply, ISDN is ageing, slow and increasingly fragile.

At the same time, it’s an opportunity for businesses of all sizes to get more from their telephony, and future-proof their communications for years to come. But with four years to go there’s no rush. Express Telephony is on hand to guide your transition whenever the time is right for you.