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ISDN & PSTN switch off. What does it mean for you?

The big switch off is coming. This article explains all about what it means and how you can get yourself ready.

This is a short guide to the ISDN and PSTN big switch off  

The ‘ISDN Switch Off,’ as it is known, will mark a significant change in the way people in the UK make phone calls.

2025 is when the switch off is happening.

It is critical for business continuity that businesses become aware of the situation and make the appropriate changes as soon as possible.

So, let’s take a look at what it is and how you can prepare for it.

What is PSTN/ISDN?

The Public Telephone Network (PSTN) is the telecommunications network which allows subscribers to communicate to different sites by voice.

The Integrated Services Digital Network (ISDN) is a communication standard which utilises a digital transmission to make phone calls, video calls, transmit data and other network services over the traditional PSTN (Public Switched Telephone Network). 

ISDN was introduced in 1986 by BT. It allowed the change from analogue phones to digital lines. A technological advancement at the time however todays standards and systems are beginning to feel the limitations of the old systems.

What is the 2025 ISDN switch off?

The main reason that the ISDN line is being cut is because despite improvements the line has become outdated. Broadband internet speeds are now faster than the maximum transfer rate of ISDN.

ISDN is also not very flexible with what you can do with it, businesses are locked to physical locations.

Now that cloud-based systems are becoming more of a norm and home working is more available to everyone, being locked to a single building due to a phone line is not longer an issue. Utilising IP telephony gives everyone more flexibility and freedom.

Why is it being switched off?

Although Openreach continually improved the line over the years they have decided that it was no longer financially profitable that they continue maintaining it. Instead they have decided to cut the line, to instead make more use of VoIP and SIP due to the improvements of broadband over the years.

Also BT have seen how popular mobile phones are and how well the coverage is from providers such as Vodafone and O2 reaching even some of the more rural areas now. Also many people no longer use their landline and some landlines don’t even make it out of the box.

How does this affect my broadband?

Broadband as we know it is changing. Gone are the days of typical broadband connections with phone lines. Traditionally you have to have a landline connection (phone line) to have broadband but soon that will no longer be the case.

So will you need to change broadband connection? Yes. The two main connections businesses and residents will need to transition onto are below:

Single Order General Ethernet Access is one of the new and improved options for homes and businesses. Utilising FTTP and FTTC, this line doesn’t come with a phone line meaning you get dedicated broadband speeds whilst being extremely reliable and easy to install.

SoGEA is a very cost effective, mainly becuase you don’t have to pay for the phone line rental on top of the broadband.

FTTP (fibre to the property)
Fibre to the Property is currently being installed nationwide. FTTP is one of the best lines that you can get if you are a home user or a business. Most properties are currently using FTTC (Fibre to the Cabinet) which is the broadband connection soon to be switched off.

FTTP is a full fibre set up, from the exchange directly to your property. Resulting in extremely fast connections and dedicated reliable speeds.

How does this affect my voice communications?

Well if you have a phone line that is connected via an Openreach box inside your property, that’ll soon no longer work. You now need to switch over to something one of the solutions listed below. Don’t see this as a bad thing, if anything it will benefit your business or home solutions.

The more popular of the two Voice Over Internet Protocol or IP telephony is a method and group of technologies that utilise your internet connection by converting the current analogue voice calls into packets of data.

These packets can be transferred like any other data packet such as emails, they can be sent over private and public networks giving you the freedom to call from anywhere.

In our opinion, VoIP is the most sophisticated phone system on the market. With plenty of features at an affordable price, it is perfect for the modern day business.

The Session Initiation Protocol (SIP) is a set of rules for initiating and terminating data transfers between participants in multimedia communications. It’s the method to make a VoIP call.

SIP is the technology that allows one or more parties on an IP network to create, modify, and terminate sessions, whether it’s a two-way call or a multi-party conference call.

Employee working

How to switch from ISDN to hosted VoIP?

The switchover is a very simple process even if you have a current phone system. You can port numbers to a VoIP system whilst retaining contacts and other features and is the best option if you already have ISDN lines going into the building.

If you are considering switching you only need to consider a few details:

  • Can your internet connection deliver VoIP? (Most providers allow this by default)
  • Can your phone system support VoIP?

Most new office phone systems support VoIP but if it doesn’t then an IP phone system will need to be setup.

We at ATS offer a full VoIP system and support for your business. We can setup everything for you getting you on the most up to date system as quickly as possible.

Benefits of switching

There are many benefits of switching sooner rather than later but also for the long haul. Below are just a few examples:


Call charges, line rental, and infrastructure costs will all be drastically reduced.

Regardless of what you’re using now, we’re convinced that switching will save you money.

Full of features

Lots of new features that will change the way you work.

On landline networks, a variety of capabilities are either unavailable or prohibitively expensive.

Voicemail, conferencing, presence status, full exchange services, switchboards, CRM integration, and more are just a few of the features available on a VoIP system.


When engaging with customers, increase the speed and efficiency of your calls.

You have complete control over your calls with VoIP. It enables you to handle consumer calls faster and more effectively than ever before, as well as indicate how well you’re doing and where you can improve.


Calls, emails, messages, scheduling, personnel status, apps, and your CRM are all combined into one single system.

Voice calls can now be brought into your digital environment, where they belong.


Disaster recovery is especially designed to recover with the least amount of downtime and data loss possible.

Keep daily ‘snapshots’ of all your data to backup all of your call records and particular customisations.

If your system crashes, we can restore the most recent usable snapshot and you’ll be back up and running in under an hour.

Future proof

The next generation of broadband and VoIP offer a future proof solution.

Once the move has been made, you can relax knowing you are on the new way of connecting and things won’t be changing again any time soon.

When are you going to switch?

The earlier the better, once VoIP phones become the norm you can expect to see their prices and wait times rise as the demand rises. Give yourself a head start over your competitors.

VoIP price plans are static, they’ll never change price within your contract period so you never have to worry about unexpected price changes mid contract.

How long does it take to switch?

From the beginning the switchover process takes around 10-14 days to get it fully up and running. We try our best to keep downtime to an absolute minimum and get you started as quickly as possible. We’ll do everything, port numbers, order phones setup accounts and all the other difficulties that take place.

Jake Boase ATS Connection
Jake Boase – Director

Failing to prepare is preparing to fail

The deadline for the switch off may seem like a long time away. but the closer we get the more complicated things become. 

Simply put, those still utilising PSTN or ISDN must change or risk becoming obsolete, unable to compete with their digitally savvy counterparts. Those who do not switch to a digital phone system by 2025 will be without operational telecommunications. 

The sooner you change to next generation broadband an a VoIP like telephone system, the more money you will save.

Will I be better off?

The switch to all-digital isn’t solely motivated by the fact that the existing phone system is, well, old. Because all-digital communications are so much more effective. 

Even at the most basic level, you’ll be able to make and receive calls from the same number on any device, from anywhere. 

You’ll integrate video chat, calls, and collaboration into your company apps and systems, bringing you closer to customers and colleagues alike. 

With everything in the cloud, you’ll be able to access systems from any location and work from any place. When you consider the lower costs that IP can provide, it’s clear that you should get on your skates and go digital as soon as possible. 

There’s no reason to not make the change now and beat the rush.


The very first way of making phone calls is coming to an end however, we have been presented with new options of connecting businesses and homes to each other utilising IP telephony which comes with better quality, cost efficiencies and ease of use.

Here at ATS we offer a fully hosted VoIP system for all size businesses and have implemented these systems to several businesses across the South Coast. If you’d like to learn more about how we can take your business to the next step, feel free to get in contact or view our packages on our website.

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