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ISDN Switch Off: A New Era in Telecommunications


Understanding The "Big Switch Off"

In 2015 BT announced it would be ending ISDN (Integrated Services Digital Network) and PSTN (Public Switched Telephone Network) services. ISDN is a technology developed for transmitting voice, video, and data over traditional copper phone lines. PSTN is voice transmitted over traditional commonly copper circuits over a large scale, connecting calls on a global scale though physical switches.

As time and technology moves on – newer, faster, and more cost-effective connections are in place, fundamentally replacing the dated ISDN and PSTN services. The Big Switch Off is already happening in many countries, marking the end of these older technologies and the rise of VoIP (Voice over Internet Protocol). This change is driven by the demand for more bandwidth, flexibility, and seamless integration with modern internet services. 

Preparing for the Switch

As businesses face the oncoming ISDN switch-off, understanding how to transition smoothly to a VoIP phone system for business is crucial. Here are some of our recommendations to prepare:

  • Talk to Your Current Communications Provider: Start by reaching out to your current provider to see their plans for the BT ISDN switch off. Discuss any plans or bundles they will be offering; this isn’t just about checking contracts – it’s about securing your communication lifeline. Ask about the new services or upgrades they offer to help you through the switch.


  • Understanding ISDN Switch Off: The “Big Switch Off” also know as the ISDN switch off will be the termination of previously mentioned ISDN and PSTN services. The ISDN and PSTN switch off means if your business still uses traditional landline systems connected by copper wires, it's time for a change! Understanding how these changes impact your business will help you ensure your connectivity isn’t disrupted and you are getting the most from your provider.


  • Look into Hosted VoIP Services: There is now no longer a need for physical cables or handsets, cloud hosted VoIP services encourage flexibility, scalability, and cost effectiveness. The move away from ISDN to hosted VoIP services reduces the need for extensive on-site equipment and all the maintenance for these – saving you the complexity and costs.


  • Engage with VoIP Service Providers: Connect with providers who understand your specific needs, like VoIP Experts, who can offer tailored solutions. Our expertise will guide you through the technical aspects of the switch and ensure your staff is well-trained.


  • Empower Your Team: Open communication and training are key. Equip your team with the knowledge and skills to use VoIP effectively. This will help them fully utilise the new system’s features, boosting your business productivity and customer service.

Our uptime commitment ensures we can operate effectively as a disaster recovery and business continuity solution – offering peace of mind for businesses who can trust in uninterrupted communication. With redundant infrastructure, automatic failover mechanisms, and cloud-based backups, VoIP Experts safeguards businesses against a lack of service.

Be prepared for the switch by implementing these steps before the end of January 2027.


The BT ISDN switch-off is more than just a technical upgrade; it’s a strategic move towards more efficient and flexible communication solutions. By understanding the key aspects and preparing accordingly, your business can turn this transition into an opportunity for growth. Embrace the future with a robust VoIP phone system for your business, supported by knowledgeable providers and an empowered team ready to take advantage of the new era in telecommunications.

Choose VoIP Experts, your trusted VoIP service provider UK, to support your business with top-notch remote working solutions.

Visit: Contact us at 0203 150 2227/