Prepare now for the PSTN switch-off

Business leaders are well aware that the PSTN switch-off is coming. The deadline has been looming for years, and while the final date has now moved to 31 January 2027, discussions of the issue have barely changed. Most public guidance, industry briefings, and migration plans continue to frame the switch-off as a technical exercise: replacing analogue lines, upgrading infrastructure, or managing a controlled transition to IP.

 

This framing is understandable, but it is incomplete. It treats the switch-off as a question of technology delivery, rather than operational dependency. In doing so, it overlooks where the real risk now sits.

 

In 2026, organisations need to understand the PSTN switch-off as a business continuity issue, with operational, financial, and safety implications that extend well beyond voice services. Treating it as an important but background project is one of the most common and costly mistakes organisations make, because it delays scrutiny of what fails when legacy connectivity degrades or disappears.

 

The question is no longer whether PSTN and ISDN services are going away. What matters now is preparedness for the deadline and beyond.

 

 

Continuity risk hides in plain sight

One of the most common misconceptions around the PSTN switch-off is that its primary impact is on phones. In practice, voice services are often the easiest element to replace.

 

The greater risk lies in the systems that depend on analogue connectivity and are rarely revisited unless they fail. Across most sectors, PSTN lines still support payment terminals, fire and intruder alarms, lifts, door entry systems, environmental monitoring, and specialist equipment in healthcare, retail, manufacturing, and public buildings. They also support ADSL, VDSL and FTTC broadband circuits, which need to be upgraded to SOGEA or FTTP. These services are designed to be invisible; when all is working as it should, no one sees the line beneath them.

 

But that invisibility is precisely the problem.

 

Many of these systems were installed years ago, certified against legacy connectivity assumptions, and never redesigned to cope with packet-based networks or variable latency. When connectivity is disrupted, the impact is immediate because these systems are not tolerant of partial failure. Payment terminals rely on stable connections to authorisation platforms. Alarm systems are contractually required to signal continuously. Lifts and access systems may fail safely, which in practice means buildings become unusable.

 

In regulated environments, loss of service can quickly escalate from operational inconvenience to a compliance issue that must be reported, investigated, and remedied within strict timeframes.

 

These risks sit squarely within business continuity planning, not day-to-day IT delivery. Yet in many organisations, there is no clear line of responsibility or accountability for them. Network teams focus on migration milestones, facilities teams assume connectivity remains unchanged, and senior decision-makers receive reassurance based on revised deadlines rather than on an understanding of how services behave under failure. Business leaders need to ensure that management reviews and upgrades all systems to All IP as soon as possible.

 

 

A transition that is already under way

While the switch-off deadline has been extended, the operating environment has already changed.

 

Since the National Stop Sell came into effect in September 2023, legacy PSTN and ISDN services have effectively been frozen. While existing lines can continue to operate, organisations can no longer expand analogue estates, carry out like-for-like migrations, or switch providers without upgrading to future-proofed services. This is not a future constraint; it is a present one.

 

Additionally, Openreach is increasing the wholesale cost of legacy lines to service providers by 20% in April 2026, 40% in June, and a further 40% by October. Organisations currently paying for analogue lines should ask themselves a simple question: how much of that increase will be passed on, and when? Most likely, this will be all or more from the day of the increase. For those whose providers have been slow to raise the topic of migration, that question may be worth asking directly.

 

 

The last-resort option may not be available

For organisations that have not yet identified what their analogue lines are being used for – and there are many – there is a growing assumption that Openreach will provide a like-for-like replacement product when the time comes. That product exists, and it is called EVAC. But it is not a default migration path. It is a last resort, intended for situations where all other options have been exhausted. There is growing speculation that Openreach will restrict this to critical national infrastructure only.

 

More importantly, Openreach has indicated that it will not confirm the terms or availability of EVAC until November. Whether EVAC will be available in your specific circumstances, based on physical infrastructure, location, and exchange conditions, will not be known until then.

 

That leaves a narrow and unforgiving window. An organisation that discovers late in November that EVAC is unavailable to them has at best, two months – including the Christmas period – to identify an alternative, procure it, and arrange installation. Engineering capacity will be under immense pressure. Lead times will be long. The likelihood of a smooth, planned outcome diminishes sharply the later the process begins.

 

 

The window to act affordably is closing

For organisations ready to move, BT has made migration more accessible than it has been at any point in this transition.

 

These conditions may not be in place indefinitely. As migration volumes increase and deadlines approach, the combination of competitive pricing, engineering availability, and planning flexibility that currently exists will tighten.

 

 

Watch out for provider inertia

One factor that receives less attention than it deserves is the role of service providers in shaping – or delaying – migration conversations. For some service providers, year-on-year above-inflation price increases have made analogue lines into high-margin products. For some smaller providers, the commercial incentive to retain customers on legacy services is significant, and the incentive to initiate a migration conversation is correspondingly weak.

 

Responsible providers are actively working to upgrade their customers’ legacy lines as quickly as possible. Not all providers are doing so. If your organisation has not yet had a serious conversation with your provider about what your analogue lines are being used for and what the migration path looks like, it is worth considering whether your provider’s commercial interests are fully aligned with yours.

 

 

The question to ask now

Every organisation with analogue lines should be able to answer the following: what are those lines currently supporting, can those services be moved to IP, and what is the plan if they cannot?

 

If those questions cannot be answered today, they will need to be answered under pressure later – with fewer options, higher costs, and less time. No operations manager wants to be explaining to their boss in early 2027 why their alarms have gone offline, their lifts have stopped working, or their payment systems have failed. They will not have been unlucky. They will simply have been too late.

 

The deadline is 2027. The time to act is now.

 

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Harry Bowlby is MD at Spitfire Network Services Ltd

 

Main image courtesy of iStockPhoto.com and scyther5