UK businesses face telecoms “cliff edge” as two thirds of network hits restrictions

New analysis from business communications provider Crystaline shows that 68.2 per cent of UK telephone exchange areas are already affected by restrictions linked to the country’s move away from copper telecoms networks. In these areas, businesses can no longer order new or upgraded traditional phone or broadband services, increasing the risk of disruption as the national transition gathers pace.

The changes form part of the UK's move away from the Public Switched Telephone Network (PSTN), the traditional copper-based telecoms infrastructure that has supported business phone lines and broadband for decades. As this network retires, businesses must move affected services to digital alternatives to maintain continuity. With the UK’s copper network switch-off entering its final phase, businesses that delay migration risk being unable to make essential connectivity changes or upgrade their services when required.

Based on Openreach stop sell data from May 2026, Crystaline’s analysis suggests that the move away from traditional copper-based services is now an active operational risk. The findings show that 68.2 per cent of UK exchange areas are already on the cliff edge where restrictions are already in force, 29.4 per cent are in the warning zone, scheduled to enter a stop sell between August 2026 and June 2027 and just 2.4 per cent remain outside a defined timeline. In total, more than 97 per cent of the UK will be affected within the next year.

The PSTN switch off is already limiting what organisations can do today. In affected areas, businesses can no longer order certain legacy services where fibre alternatives exist, making it harder, or even impossible, to change, expand or fix existing systems at short notice.

“Many businesses still see the copper switch off as something happening in the future, but with the stop sell, the transition is already here,” said Kristian Torode, Director and Co-Founder of Crystaline. “For businesses still relying on old phone lines, the window to act is getting smaller. This is no longer just an infrastructure change, but a business-critical continuity issue.”

The impact goes beyond phone calls. The PSTN supports a wide range of business-critical services, including broadband connections, payment terminals, alarm systems, lift emergency lines and entry systems. Many of these dependencies remain invisible until a service needs to be upgraded, repaired or replaced.

Crystaline warns that businesses leaving migration plans until late 2026 could face increasing delays as demand for installations grows. With a typical migration taking 30 to 60 days, businesses leaving it late may face delays with surveys, installations and number transfers as providers handle a surge in demand.

“Autumn is likely to be a crunch point,” Torode added. “If too many organisations try to move at once, there will be pressure across the industry. The risk is not the deadline, but whether businesses can complete their migration in time, and that’s getting harder to guarantee.

“The UK is standing on a copper cliff, and businesses are closer to the edge than they think,” said Torode. “The safest approach is to identify every service that depends on a legacy line and start planning migration now. Waiting until a service fails or an order is blocked leaves too much to chance.”