The Big PSTN Switch Off: What Does it Mean For Your Business?

Off button icon with a telephone in front of it depicting the pstn switch off

The Big PSTN Switch Off refers to the planned shutdown of the Public Switched Telephone Network (PSTN) in the UK by 2025. PSTN is the traditional telephone network that has been in use since 1875, and it supports various services, including analogue phone lines, broadband, alarm systems, and CCTV cameras. BT Openreach has decided to switch off the PSTN network due to its outdated technology and inability to support the speed, scalability, and methods of communication that businesses require today.

Alongside this, ISDN lines will also be shut down. ISDN stands for Integrated Services Digital Network, which is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network. It was introduced in 1986 by BT as a way to replace outdated landline technology with digital lines and added features that were not available with a classic telephone system.

ISDN provides high-speed, high-bandwidth channels to every subscriber on the public switched telephone network, achieving end-to-end digital functions with standard equipment interface devices. It enables a variety of mixed digital transmission services to be accommodated at a single interface, and multiple devices can be attached to the line and used as needed.

ISDN has largely disappeared on the customer side, remaining in use only in niche roles like dedicated teleconferencing systems and similar legacy systems. The switch-off of PSTN and ISDN networks will require consumers to adopt alternative solutions such as VoIP for voice services.

The switch-off will have significant implications for businesses and other organisations, as you will need to transition from PSTN-based services to alternative solutions, such as Voice over Internet Protocol (VoIP). VoIP allows conventional phones to operate over computer networks, transmitting calls through the internet instead of physical phone lines.

Key Dates

  • 15th September 2023: Any broadband or phone services that use the old copper public switch telephone network will no longer be sold, including ISDN lines.
  • April to December 2025: Forced migration phase for ISDN and PSTN lines.
  • December 2025: The national grid of both ISDN and PSTN lines will be switched off, and ISDN circuits will no longer be supported

It is essential for businesses and individuals to prepare for these dates and transition to alternative solutions, such as VoIP, before the PSTN switch-off in 2025.

How Should Businesses Prepare for the PSTN switch off?

To prepare for the Big PSTN Switch Off, businesses should:

  • Audit their existing phone system, equipment, and network to identify any dependencies on PSTN
  • Research and select a suitable VoIP provider that meets their specific needs and requirements
  • Implement the new VoIP system and train employees on how to use it
  • Review and update any other systems or services that rely on PSTN, such as lifts, alarms, fax machines, and payment terminals
  • By transitioning to VoIP before the PSTN switch-off in 2025, businesses can ensure uninterrupted communication and take advantage of the numerous benefits of VoIP technology, such as cost savings, increased flexibility, and advanced features

Contact us today to see how we can support your switch to VoIP.

How Should Businesses Prepare for the ISDN switch off?

1. Assess current infrastructure: Businesses should evaluate their current telecommunication infrastructure to determine if they are still relying on ISDN. This includes identifying any phone systems, equipment, or services that are dependent on ISDN.

2. Research alternative solutions: Businesses should research and explore alternative communication solutions that will replace ISDN. This could include Voice over IP (VoIP) systems, cloud-based phone systems, or other modern communication technologies. It is important to consider the specific needs and requirements of the business when choosing a new solution. If you need support in determining your requirements, we’re able to assess your business needs and come up with an effective solution.

3. Plan and budget for the transition: Once an alternative solution has been identified, businesses should create a detailed plan for transitioning from ISDN to the new technology. This plan should include a timeline, budget, and any necessary resources or support. It is important to allocate sufficient time and resources for the transition to avoid any disruptions to business operations.

4. Communicate with stakeholders: Businesses should inform their employees, customers, and other stakeholders about the upcoming switch off of ISDN. This includes educating them about the reasons for the switch-off and the benefits of the new technology. Clear and effective communication will help manage expectations and minimise any potential disruptions.

5. Upgrade or replace equipment: Depending on the chosen alternative solution, businesses may need to upgrade or replace their existing phone systems and equipment. This may involve purchasing new hardware and software or subscribing to new services. It is important to coordinate with vendors or service providers to ensure a smooth transition.

6. Test and train: Before fully transitioning to the new technology, businesses should conduct thorough testing to ensure compatibility and functionality. Additionally, employees should be trained on how to use the new communication system effectively. This will help minimise any learning curve and ensure a seamless transition.

7. Monitor and troubleshoot: After the switch off, businesses should closely monitor the new communication system to identify any potential issues or areas for improvement. It is important to have a support system in place to address any technical issues promptly and minimise downtime.

By following these steps, businesses can effectively prepare for the ISDN switch-off and ensure a smooth transition to a modern and efficient communication solution.

Why is Openreach withdrawing the PSTN and ISDN network?

The PSTN and ISDN networks have become outdated technologies. The PSTN, which has been the backbone of the UK’s telecommunications system since 1876, and ISDN, introduced in the 1980s, are both antiquated and costly to maintain. These copper wire-based telephone networks have remained largely unchanged since their inception, making them inefficient for modern communication needs.

The lack of scalability and speed with the ageing technologies of PSTN and ISDN has become a challenge. As businesses grow and communication requirements increase, maintaining and upgrading these networks has become more expensive and difficult. This limitation hinders the ability to scale and provide the speed required for efficient communication in today’s fast-paced business environment.

The PSTN and ISDN networks cannot effectively support modern communication methods. The emergence of newer technologies, such as fibre broadband, offers better support for modern communication methods. These technologies provide faster and more reliable connections, enabling businesses to adopt advanced communication tools such as VoIP (Voice over Internet Protocol) and cloud-based services.

Openreach’s decision to switch off the PSTN and ISDN network is driven by the transition to digital and IP-based solutions. By paving the way for an all-IP network, Openreach aims to provide a more efficient and flexible infrastructure for communication services. This transition will enable businesses to take advantage of the benefits offered by digital and IP-based technologies, such as improved reliability, scalability, and integration with other digital services.

As Woodstock IT, we understand the challenges businesses may face during this transition. We are equipped to support businesses in migrating to a high-availability fibre-first network with minimal disruption. Our team of experts can assist with the installation, configuration, and ongoing maintenance of new communication systems, ensuring a smooth and seamless transition for businesses. With our support, businesses can embrace the opportunities presented by modern communication technologies and stay ahead in today’s digitally-driven world.

What is replacing PSTN and ISDN?

VoIP, or Voice over Internet Protocol, phone systems are replacing PSTN and ISDN networks. VoIP allows for the transmission of voice and multimedia communication over the internet, rather than traditional copper wires. This technology converts voice into digital data packets and sends them over an IP network.

There are several reasons why VoIP is replacing PSTN and ISDN:

1. Cost-effectiveness: VoIP phone systems are generally more cost-effective compared to traditional phone systems. Calls made using VoIP are typically cheaper, especially for long-distance and international calls, as they are transmitted over the Internet rather than through traditional phone lines.

2. Scalability and flexibility: VoIP phone systems offer greater scalability and flexibility. They can easily accommodate additional users or lines without the need for physical infrastructure changes. This makes it easier for businesses to scale up or down their communication needs as required.

3. Advanced features and functionality: VoIP phone systems offer a wide range of advanced features and functionality that enhance communication capabilities. These include call forwarding, call waiting, auto-attendant, voicemail-to-email transcription, and integration with other business applications. These features can improve productivity and streamline communication processes.

4. Mobility and remote work: VoIP phone systems enable users to make and receive calls from any location with an internet connection. This is particularly beneficial for businesses with remote or mobile workers who need to stay connected and accessible regardless of their physical location.

5. Integration with other communication channels: VoIP phone systems can easily integrate with other communication channels, such as video conferencing, instant messaging, and email. This allows for a more unified and streamlined communication experience, enhancing collaboration and productivity.

6. Future-proof technology: As technology continues to advance, VoIP phone systems are well-positioned to adapt and incorporate new features and capabilities. This makes them a future-proof choice for businesses looking to invest in a long-term communication solution.

Overall, VoIP phone systems offer a cost-effective, scalable, and feature-rich alternative to traditional PSTN and ISDN networks. With their ability to support modern communication methods and provide a more efficient infrastructure, VoIP is a logical replacement for the outdated and costly PSTN and ISDN technologies.


Can Digital Voice Services work during a power cut?

Yes, Digital Voice Services can work during a power cut. Unlike traditional PSTN and ISDN networks that rely on copper wires and physical infrastructure, Digital Voice Services operate over internet protocol (IP) networks. This means that as long as there is an internet connection available, VoIP Services can continue to function during a power outage. Additionally, many service providers offer backup power options, such as battery backups or generators, to ensure continued service even in the event of a power cut.

What lines and services, such as alarms and payment terminals, will be impacted by the closure in 2025?

Lines and services such as WLR, ISDN2, ISDN30, LLUSMPF, Narrowband Line Share, Classic Products, ADSL Broadband, and FTTC Broadband will be impacted by the closure in 2025.
This means that any alarms and payment terminals that rely on these lines and services will no longer be operational after the closure.

What legacy devices and systems will stop working from 2025?

The withdrawal of PSTN and ISDN networks will affect several legacy devices and systems that rely on these networks. Here are some examples:
Analogue phones and fax machines: Analogue phones and fax machines will no longer work after the PSTN switch-off in 2025.
Alarm systems: Alarm systems that rely on PSTN or ISDN networks, such as fire alarms, burglar alarms, and panic alarms, will need to be upgraded to alternative solutions.
Payment terminals: Payment terminals that use PSTN or ISDN networks, such as card readers and cash machines, will need to be upgraded to alternative solutions.
Lifts and elevators: Lifts and elevators that use PSTN or ISDN networks for communication will need to be upgraded to alternative solutions.
Intercom systems: Intercom systems that use PSTN or ISDN networks for communication will need to be upgraded to alternative solutions.
Broadband services: Broadband services that rely on PSTN, such as ADSL and FTTC, will no longer be available after the PSTN switch-off in 2025.
Landline voice services: Traditional landline voice services will cease to operate after the PSTN switch-off in 2025, and consumers will need to switch to alternative voice services, such as VoIP, to maintain uninterrupted communication.

How Woodstock IT can help

Are you worried about the upcoming PSTN and ISDN switch-off and the impact it will have on your business communication systems? Look no further! Woodstock IT is here to help you audit, install, and implement VoIP services seamlessly, ensuring a smooth transition and uninterrupted connectivity.

Our team of experts will conduct a thorough audit of your current systems to assess their compatibility with VoIP technology. We will identify any potential challenges or areas that require improvement to ensure a hassle-free migration. With our extensive experience in the field, we will provide you with personalised solutions tailored to your specific business needs.

Once the audit is complete, our skilled technicians will handle the installation and implementation of VoIP services for you. We understand that every business is unique, and therefore, we will customise the setup to meet your exact requirements. Our goal is to minimise business disruption to your daily operations while maximising the benefits of VoIP technology.

But our support doesn’t end there. Woodstock IT is committed to providing proactive measures to ensure the smooth functioning of your communication systems. Our team will closely monitor your VoIP services, constantly analysing performance and identifying potential issues before they escalate. With our proactive approach, we aim to keep your business communication up and running without any interruptions.

Contact Woodstock IT today and let us help you embrace the future of business communication!

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