By January 2027, the UK’s Public Switched Telephone Network (PSTN) will be permanently retired. For IoT and connected systems, this is more than a telecoms update — it’s a fundamental change in how devices communicate, triggering a nationwide infrastructure reset.
Why the PSTN Is Ending
The PSTN has been the backbone of UK communications for decades, supporting analogue lines and ISDN services. As technology evolves, copper networks are no longer sustainable. Openreach is transitioning the country to an all-IP future using fibre and mobile networks.
All services based on Wholesale Line Rental (WLR) — including traditional landlines, ISDN2, and ISDN30 — will be retired.
Impact on IoT and Connected Devices
Copper lines still quietly support thousands of critical and IoT-linked systems, including:
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Telecare and social alarms
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Building management systems
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Fire and security alarms
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Lift emergency call units
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Access control and entry systems
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Legacy utility monitoring equipment
These systems are often installed deep within buildings or linked to long-standing contracts. The shutdown exposes hidden dependencies that many organisations are unaware of.
The Exchange Rationalisation Factor
As part of the shutdown, Openreach will reduce UK telephone exchanges from around 5,500 to 1,000. This lowers costs but disrupts traditional redundancy. Fibre is strong but not immune to local risks such as roadworks, power loss, and flooding.
Why Fibre Doesn’t Always Fit IoT Deployments
For many IoT deployments, fibre is impractical. Running fibre into lifts, retrofitting it for alarm panels, or trenching it into remote assets can be both disruptive and costly.
Cellular connectivity, particularly 4G and 5G, is better suited for many IoT use cases. It provides flexibility, reliability, and rapid deployment — without the constraints of fixed cabling.
Preparing for the 2027 PSTN Shutdown
To protect IoT and business-critical systems, organisations should:
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Audit all connected devices and services reliant on copper.
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Assess building systems and legacy installations for hidden dependencies.
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Explore next-generation connectivity — fibre, cellular, or hybrid models.
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Prioritise resilience and continuity planning.
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Begin transition planning now — delays could lead to rushed and costly replacements.
Conclusion
The PSTN switch-off is not just about ending traditional voice services — it’s about reshaping how IoT and critical systems stay connected. For UK businesses and organisations, this is an opportunity to modernise infrastructure, adopt resilient cellular solutions, and prepare for the future of smart, connected operations.
