The way we communicate is undergoing a dramatic transformation in the United Kingdom. And, it’s essential to stay ahead of the curve. By December 2025, traditional analogue phone networks will be phased out. That includes the public switched telephone network (PSTN)—the traditional copper phone line—and integrated services digital network (ISDN)—digital phone lines. These will be replaced with newer, more efficient, and versatile communication technologies.
In this article, we will delve into the why, the how, and the what’s next of this monumental shift in the telecom landscape.
Understanding the Transition
Leading telecom providers, including BT, are taking the bold step of discontinuing PSTN and ISDN services. To grasp the magnitude of this change, it’s crucial to understand why it’s happening.
This isn’t just about phone lines; it’s a broader move toward fully digital networks that use Internet Protocol (IP) over fibre-based services. The shift is due to the need for better technology that can meet the demands of our changing digital world.
Preparing for Change
As we approach the deadline, the clock is ticking for individuals, businesses, and organisations to adapt. In order to do that, you’d need to switch to one of two options—voice over internet protocol (VoIP) or mobile networks.
VoIP services allow you to make calls over the internet using a broadband connection. To use VoIP, you must subscribe to a service provider, get compatible hardware (such as IP phones or analogue telephone adapters), and set up the required configurations. While this may mean acquiring a new phone number, some providers offer the option to retain your existing one.
Mobile Network Systems
Alternatively, you can make the switch to mobile networks by using mobile or smartphones. This entails selecting a mobile service provider, obtaining a SIM card, and activating a mobile plan.
Why the Change Matters
This transition isn’t just about upgrading technology; it’s about embracing a future where communication is more flexible, cost-effective, and reliable. Traditional landline phone services, which have served us for decades, will cease to function. This change is not unique to the UK; many countries worldwide are planning similar shifts.
The transition affects various services and organisations, from alarms and CCTV systems to door entry products. Integral to this shift is the role of ISDN. It has been the standard connectivity to PSTN for years but is no longer up to the task.
Instead, session initiation protocol (SIP) Trunking emerges as the solution, delivering PSTN connectivity over IP networks. It not only maintains inbound and outbound call capabilities but also offers additional features and enhanced flexibility.
The Impact on Contact Centers
For contact centres, this transition represents a significant transformation. Here’s how it will affect them.
Contact centres relying on traditional PSTN or ISDN lines will need to upgrade their telephony infrastructure. This may involve investing in new hardware and software solutions, such as IP phones and call centre software designed for VoIP.
VoIP and SIP Trunking often offer lower call rates and reduced operational costs compared to traditional phone lines, resulting in cost savings for contact centres.
These technologies provide greater scalability, allowing contact centres to adjust capacity according to their needs, crucial for managing fluctuating call volumes.
VoIP and SIP Trunking provide useful features like call routing, call recording, IVR, and CRM integration to improve customer service and efficiency.
Agents can handle calls and provide customer support from anywhere with an internet connection. That provides businesses with flexibility and access to a broader talent pool.
Improved Customer Experience
Advanced features and integration capabilities lead to a more seamless and personalised customer experience, reducing wait times and improving satisfaction.
Redundancy and Reliability
VoIP and SIP Trunking often offer redundancy options to ensure continuous service in case of network disruptions, maintaining high availability.
Contact centres must carefully plan the transition to avoid disruptions. This includes migrating phone numbers, training agents on new technology, and conducting thorough testing. It’s important to find reliable testing services such as Occam Networks to weed out any potential glitches in the systems.
Compliance and Security
Contact centres must ensure compliance with industry regulations and maintain robust security measures to protect customer data.
Monitoring and Analytics
VoIP and SIP Trunking provide monitoring and analytics tools for tracking call metrics, agent performance, and customer interactions, optimising operations.
Key Dates and Preparation For the Transition
Openreach, a major telecom industry player, has stopped selling PSTN and ISDN services to new customers since September 2023. There will be no further upgrades or features available for existing customers. To ensure continuity of service, early preparation is paramount. You’d need to review and identify all the hardware and functions connected to and working through phone lines, including lift phones, fax machines, and CCTV systems.
Market Opportunities For Smaller Telecom Service Providers
The transition also presents market opportunities for smaller telecom service providers. Ofcom and the UK Government have mandated the switch-off to reduce network operation costs and transition to efficient fibre technologies. Smaller providers can seize this opportunity by offering innovative connectivity solutions to businesses. These solutions are quicker and easier to implement than transferring telecom services, making them attractive options.
The PSTN switch-off in December 2025 marks a significant milestone in the evolution of UK telecom networks. To ensure a seamless transition and avoid communication disruptions, early preparation is paramount. Whether you opt for VoIP or SIP Trunking, these changes offer opportunities for cost savings, enhanced functionality, and future-proofing your telecom infrastructure.
Contact centres that embrace this transition can position themselves for greater efficiency and competitiveness in the evolving telecommunications landscape. Stay informed, be proactive, and embrace the benefits of a digital future in telecommunications.
Parul Mathur has been writing since 2009. That’s when she discovered her love for SEO and how it works. She developed an interest in learning HTML and CSS a couple of years later, and React in 2020. When she’s not writing, she’s either reading, walking her dog, messing up her garden, or doodling.