With 12 months remaining until the PSTN switch-off, Openreach is issuing a stark warning to British businesses to unchain their network from legacy copper infrastructure or face rising costs and connectivity issues.

The humble copper wire has been the backbone of our telecommunications here in the UK and around the world for over a century, keeping our hospitals, schools, and emergency services connected and powering everything from card machines on our high streets to vending machines, smart meters, CCTV, and even sluice gates.

During this time, most phone calls in the UK have been handled by BT’s copper -based public switched telephone network (PSTN), an analogue system which connects people using specific phone numbers.

But being around for as long as it has, the PSTN’s become outdated and difficult to maintain. Skills and parts are increasingly difficult to come by and new digital services like Voice over IP (VoIP) – where voice calls are transmitted the same way your broadband works are becoming the norm.

Openreach’s parent, BT Group will retire the PSTN network by 31st January 2027 – and Openreach has been working to withdraw any Openreach products that work over it – which come under the umbrella term of Wholesale Line Rental (WLR).

As the January 2027 deadline enters its final countdown, Openreach has made clear that all technical barriers to migration – including protections for vulnerable telecare users – have been resolved. Consequently, the deadline is locked, and the focus has shifted to the urgent withdrawal of legacy copper products.

There are currently still roughly 2.8m lines on the PSTN network that need to migrate – with more than half a million of those serving business premises. CPs and businesses that fail to migrate will face these higher charges before losing service altogether as the network is phased out.

“There’s no time left to stall,” James Lilley, Director of All-IP at Openreach, said.

“We’ve spent the last year ensuring telecare customers can be migrated safely through our ‘Prove Telecare’ service, removing the final barrier to the switch-off.

“Now, the reality is simple. The PSTN analogue network is obsolete, becoming harder to maintain and significantly more expensive to run. We are passing those costs on to providers who continue to sell legacy products.

Recommended reading

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• 2025 Analogue Phone Line Switch-off: Are Businesses Ready

“If your business is still on this copper service, you will start to pay a premium for a service that will be switched off in 12 months. Most major Communications Providers moved their customers to digital long ago. If your provider hasn’t contacted you, you need to ask why.”

While many Communication Providers (CPs) have already migrated much of their customer base, a number of smaller or specialist providers have been slower to act. Openreach warns that businesses remaining with these providers face unique risks tied to equipment failure. Beyond phones, critical hardware including fire alarms, burglar alarms and payment terminals, will need to be migrated: the latest data reveals more than 12k lift lines and around 500 lines serving CCTV networks need to be upgraded.

Openreach suggests that businesses that have yet to make the switch to review their assets, test their equipment can be done for free at Openreach’s test labs, and finally, switch to a digital solution as soon as possible.