Feature
August 11, 2021
2025 ISDN Switch Off - The Complete Guide

A Complete Guide to the 2025 ISDN Switch Off

Read time:
4 Minutes

In 2025, the UK’s ISDN network is being switched off in favour of digital, IP communications.

The switch off was announced in 2018, with network operators given seven years to being switching their technologies.


If your business is concerned about the impact of the ISDN switch off, this guide is here to help you find out how you can switch to digital communications and get your business ready for the ISDN switch off in 2025.


What is ISDN?

Let’s start at the beginning. ISDN is an acronym for Integrated Services Digital Network. Essentially, ISDN is the networks that make up the UK’s telephone infrastructure. ISDN was first introduced in the UK in1985.


Before wide adoption of the internet, making a telephone call meant that your telephone had to be physically connected to another, in most cases, this was using a cable between one handset and another. Because every phone had to be connected, there had to be a large infrastructure in place to connect these calls.


ISDN Diagram
ISDN vs VoIP Diagram


In the early 2000s, with the internet gaining popularity, the ISDN was used to deliver broadband connectivity, as well as telephone calls. This is how most businesses and consumers accessed the internet.


It was common to have both ‘line rental’, for the telephone line, and broadband rental, for the internet package on that line.


As you can probably imagine, a technology invented in 1985 is no longer fit for purpose. With internet usage vastly outstripping landline usage, and with the advent of VoIP, ISDN was no longer the best option.


What is ISDN
What is ISDN?

Why is ISDN being switched off?

The UK’s ISDN is being turned off because it is no longer fit for purpose. It uses older, outdated technologies and is not able to keep up with the demand of modern broadband usage.


Fibre broadband has been a key accelerator in the demise of ISDN, with a substantial percentage of the UK’s ISDN being converted to fibre optic, which is a far superior technology for both speeds and latency.


Many businesses and residential properties have moved their broadband and telephony systems over to digital, fibre optic infrastructure in preparation for the switch off in 2025.

UK’s ISDN Switch Off Key Statistics

Here’s a few key statistics to about the ISDN switch off in 2025:


ISDN switch off key statistics
ISDN switch off key statistics

According to a study on Statista, there has been a 96% decrease in ISDN orders over the past 10 years. This is a clear indication that consumers and businesses are moving to newer technologies.


Our team estimate up to 90% cost saving when users switch to non-ISDN services such as fibre broadband and VoIP.


50% of business owners don’t know that the switch off is coming, and Microscope estimate that over 80% of businesses don’t know when their ISDN services will become obsolete. 


Some of these statistics are quite worrying, and that is why it is important to understand what/when/how the ISDN will affect your business.

How to Prepare for the ISDN Switch Off

Here’s some steps that you can take to prepare for the ISDN switch off:


1. Firstly, don’t panic.

The ISDN will keep running for a few more years yet, so you still have time to put the ground work in to move away from ISDN technologies.


Also, we’re here to guide you through the maze of telecoms terminology and help find the right solution for your business that suits both budget and requirements. Our team can provide honest advice about ISDN and what your business might require.


2. Think about your business

The first step in moving away from ISDN is taking time to understand what your business actually needs. Ask yourself how many telephones you need? Do you need home working? What broadband speed do you require?


Building up a picture of your current and required communications is important as it allows us to help build a solution to your businesses needs.


3. Look at your options

Alternative technologies, often known as ‘digital’ or ‘IP’ communications are the direct replacement for ISDN. These often include, fibre broadband, SOGEA broadband, VoIP and SIP Trunks.


Yep, that is a lot of acronyms, but our team are here to guide you through these acronyms and help you understand which option is best for your business.


4. Get in touch 

We’ve said it before and we’ll say it again, we’re here to help. Our team are here to provide honest advice for your business, taking time to understand your requirements and give you a view of your best available options.


Getting ready for ISDN switch off
Getting ready for ISDN switch off

ISDN: What are the Replacements?

There are so many options available to businesses that are planning to make the move away from ISDN. From cloud based telephone systems to SOGEA and SIP. Here’s a little more detail about each option and how your business could benefit from them…


1. Cloud telephone systems

Rather than traditntal, on-premise telephone systems, cloud-based solutions remove the need for expensive hardware and leasing, instead opting for simple, user-based licensing. 


Using our cloud platform, you can customise call flow, allow seamless home working and benefit from IP-ready communication features at the fraction of the cost of a traditional on-premise or PBX solution.


Another great benefit of cloud telephony is the reduction (if not elimination) of call charges. Businesses often spend thousands of pounds a year just to make and receive telephone calls—but this is not the case with our cloud based phone system.


Cloud telephone systems with VoIP
Cloud telephone systems replace ISDN


2. SOGEA Broadband

Traditional ISDN broadband lines require line rental, where you pay for a telephone line with broadband on top of this line. However, the advent of SOGEA has removed the requirement for line rental, just providing you with one simple broadband line.


SOGEA broadband uses the UK’s fibre infrastructure to achieve superfast speeds, all without using the ISDN.


We’ve helped businesses save money on their monthly running costs by moving their broadband over to SOGEA and getting rid of costly and unnecessary line rental. Speak to a member of our team to see if SOGEA is available for your business.


3. SIP Trunks & VoIP

SIP and VoIP are two variations of the same technology. Essentially, they turn your existing broadband connection into a voice and data line. 


With traditional ISDN, a business would need multiple telephone lines to make concurrent calls, but this is not the case with VoIP or SIP. Reducing these lines allows your business to save money and eliminate these line charges and some call costs too.


Preparing for the ISDN switch off
Prepare for the ISDN switch off


As you can tell, there are lots of different options available to you when you upgrade to IP communications and move away from ISDN.

Benefits of IP-ready Communications

You have probably already picked up on the running theme here, and that is that moving away from ISDN comes with a lot of benefits. 


A lot of businesses see the ISDN switch off as a punishment, a looming evil that will cripple their telecoms—but this really is not the case. The ISDN switch off is a way to eliminate old technology from the UK’s infrastructure, and improve everyones lives.


Benefits of digital communications
Benefits of digital communications


There are so many costs to be saved and additional features to benefit from that it would be too long to list them all in this article. But here is a snapshot:


Seamless home working; reduced line rental; little to no call charges; collaboration features between colleagues; faster broadband speeds; future proof solutions; no system maintenance or leasing; better use of broadband connections; higher quality voice calls; integration with mobile phones; customisable solutions and call flows; CRM integration and screen popping; more up-to-date hardware; and many, many more.

ISDN Switch off - Next Steps

If you’re thinking of upgrading, or your telecoms are up for review, get in touch with our team and we’ll help you understand the options available and talk you through which technologies suit your business the best.


No sales talk, just honest, no-obligations advice that is tailored to your business.


ISDN switch off
Your next steps

If you have any questions, or would like some more information about how Bytes Digital can help your business, email hello@bytesdigital.co.uk give us a call on 03331 301 021.

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