The BT 2025 ISDN Switch-Off: How Will It Affect Schools and Higher Education?

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    In 2025, a major change is coming to the UK’s telephony and communications infrastructure, and it is one that every single home, business and organisation across the country will need to be ready for.

    BT and Openreach have confirmed that from 2025, the UK’s integrated services digital network (ISDN) and public switched telephone network (PSTN) circuits – which underpin many internet and telephone connections still in use across the country – will be switched off for good, as part of efforts to modernise the nation’s internet solutions and services.

    For any schools and educational institutions that still rely on these older technologies, this means it is essential to upgrade and replace your older equipment in order to stay connected, and to prevent any disruption when the switch-off takes place.

    Here, the experts at Fuse 2 Communications provide you with everything you need to know about BT’s 2025 ISDN switch-off, including why it’s happening, what it will affect, and what your organisation needs to do to ensure your essential communication tools are ready for the future.

    What Is ISDN?

    ISDN is the communication standard that has allowed for simultaneous digital transmission of voice, video, data and other network services through public telephone lines. This represented a real technological breakthrough in the late 1980s and early 1990s, paving the way for many of the modern internet-based communications innovations we use today.

    However, in the intervening years, ISDN has largely been superseded by newer technology standards, such as higher-speed digital subscriber line (DSL) systems, and is now largely considered obsolete.

    What Is PSTN?

    PSTN is the term used to describe the UK’s traditional telephone line network, which carries analogue voice data over a nationwide network of copper lines. This technology has much older roots than ISDN, and has essentially served as the standard for telephone communication since the late 1800s.

    As such, many homes and businesses across the UK still rely on PSTN connections to make landline phone calls and send faxes, despite the fact that this 19th-century technology is no longer fit for purpose in the modern world of digital communication.


    The 2025 ISDN switch-off is happening as part of BT’s broader transition to an all-digital communications network for the UK. This process has already begun, and 2025 will be the end of a years-long transition process – which is why now is the time to get educated on why this is happening.

    Why Are These Services Being Switched Off?

    The bodies responsible for developing and updating the UK’s communications networks are looking to make a clean break from outdated legacy technologies, such as ISDN and PSTN, which are no longer seen as fit for purpose in this new era of video conferencing, cloud services and always-online digital innovations.

    As such, these services are being decommissioned, with every phone line in the UK switching over to digital services. Calls will now be routed over via IP (Internet Protocol) instead of PSTN, a move that will bring new and more advanced services to the entire nation. This will also bring the UK in line with other countries that are making or have made a similar transition, such as Germany, Japan, Sweden and the Netherlands.

    As part of this process, sales of new systems using ISDN and PSTN technology ceased in 2020, while businesses will no longer be able to order ISDN lines after 2023. This will pave the way for the complete discontinuation of the old services in 2025.

    How Will The BT ISDN Switch-Off Affect The Education Sector?

    For schools, universities and other educational institutions across the UK, the biggest consequence of the ISDN and PSTN switch-off is obvious: any premises that are still using ISDN and PSTN must upgrade as soon as possible.

    Although many organisations have already made this switch, it is likely that some have still not made the transition, while others may not even be aware that this is happening. A survey from 2017, around the time when the switch-off was announced, indicated that 42% of small and medium-sized organisations in the UK still used analogue lines to transmit data, as well as 33% of large businesses; this number will certainly have come down since then, but could still include a large number of schools and higher education facilities.

    By failing to properly prepare for this switchover, your institution could be caught unawares by the switch-off, leading to disruptions in your essential communications as the 2025 deadline approaches. This will make it harder to research and smoothly implement a new IP setup that meets your needs.

    How Should Schools And Higher Education Prepare For The 2025 ISDN Switch-Off?

    In order to ensure your facility is ready for the switch-off of ISDN and PSTN services, it is important to review your current comms setup and make sure you have everything you need to be ready for this important transition. Here are a few of the key steps you should be considering:

    Check which of your current systems and devices are connected via ISDN or PSTN

    Your first step should be to take stock of your current communication solutions and work out which of your systems, devices and infrastructure need to be replaced in order to be ready for 2025.

    Naturally, this will start by reviewing your existing handsets, internet connections and phone lines, but it is also vital to remember that there may be other systems and services that depend on PSTN technology that you may have overlooked. Examples of this include fax lines, door entry systems, alarm systems, emergency lines for lifts and elevators, or payment terminals and cash machines.

    Make sure you have been comprehensive in your review to avoid any risk of possible oversights.

    Upgrade your broadband internet connection if necessary

    If your school is switching to internet-based communications, it stands to reason that you will need an enterprise-grade broadband connection that is capable of carrying all of the data necessary to support your future voice and video calls, as well as your staff and students’ on-site internet usage.

    If your existing internet service lacks speed or reliability, it may be time to invest in an upgrade. You should realistically assess your facility’s current usage trends, based on the number of on-site users, and seek out a reliable provider of internet services, such as Fuse 2 Communications, that will be able to meet your current and future needs.

    Arrange a switch to VoIP services

    The 2025 ISDN and PSTN switch-off will mean leaving analogue telephone communications behind to embrace the potential offered by modern VoIP (voice over internet protocol) technology, which will allow your voice calls to be sent using your internet connection.

    By speaking to a specialist provider of VoIP and smart IP communication services such as Fuse 2, you will be able to get set up with a state-of-the-art digital telephony infrastructure, with calling services hosted either on your premises or via a highly secure enterprise-grade external hosting service. This will allow your school to carry on making calls and communicating as normal up to 2025 and beyond.

    Your provider will be able to talk you through each of the steps necessary to migrate seamlessly from your legacy systems to the new IP infrastructure, including any on-site changes that need to be made or equipment that must be replaced.

    Replace or upgrade your communications hardware

    As part of this upgrade process, it will be necessary to review your existing communications hardware, including phone handsets and other similar systems, and determine which of them need to be replaced to work with your new IP communications setup.

    In many cases, you will be able to simply upgrade your legacy systems via a service called call forking, which allows you to merge your existing on-premise calling system with VoIP cloud capabilities. By adapting your existing phone lines and services to make calls over the internet, you can ensure greater continuity for your team, while also making sure that your existing infrastructure investments do not go to waste.

    If you are interested in setting up call forking, you should ask your provider for guidance on how best to go about this.

    Involve your whole team in your transition planning

    Any major change within an organisation can be disruptive unless it is planned properly, which is why it is important to let all of your school’s faculty and staff know about the transition to IP communications, and brief them on what they will need to do to adapt to the new system.

    As part of this, you should look to designate a team member who will be responsible for coordinating this transition, ensuring everyone within your organisation has a recognised point of contact. If there is nobody suitable within your team to take this responsibility on, your IP service provider may be able to provide you with additional support.

    What are the advantages of making this change?

    The 2025 ISDN switch-off creates responsibilities for schools and education providers to review their communication setups and make changes where necessary. However, the change will also bring numerous benefits with it, meaning this is more than a mere obligation.

    Here are just a few of the significant advantages of making the switch to smart IP communications:

    • Gain the ability to make and receive calls from any device in any location, using your existing phone numbers
    • Link together your various administrative and comms applications and systems, including video chat, calls and collaboration tools, to ensure you are able to handle admin tasks more seamlessly
    • Save considerable amounts of time and money in the long term by embracing free VoIP calling and modern efficiency tools, and by unifying your communications infrastructure under a single service
    • Take advantage of the clear, responsive call quality, consistent reliability and enterprise-standard security offered by modern smart IP communications
    • Adapt your existing systems to work with your new IP setup, meaning you can complement your existing infrastructure rather than having to totally replace it with expensive new gear
    • Deliver future-proof communications tools and digital infrastructure to meet the needs of modern students and teachers, including video conferencing and always-on web services

    Fuse 2 has migrated some very prestigious schools and academies of all sizes across the UK onto Microsoft Teams directing routing, making it their primary phone system. The solution allows you to port and use existing telephone numbers, as well as enables on-premise systems to work seamlessly with Microsoft Teams, which is known as call forking.

    One of the reasons this solution is so attractive to schools, colleges and universities is the level of discount they receive on the Microsoft licences.